Keith Christian

Dehydration enhances innate immunity in a semiaquatic snake from the wet-dry tropics

Publisher: Wiley

Date: 14-03-2019

DOI: 10.1002/JEZ.2260

Abstract: Dehydration is considered a physiological challenge, and many organisms live in environments that undergo periods of reduced water availability that can lead to dehydration. Recent studies have found a positive relationship between dehydration and innate immune function in animals adapted to xeric or semixeric environments. To explore the generality of this relationship, we examined the impact of dehydration on innate immune performance in water pythons (Liasis fuscus), a semiaquatic snake from the wet-dry tropics of Australia. We collected blood s les from male and female water pythons held in the laboratory without food and water for 4 weeks. We also collected blood from free-ranging snakes throughout the Austral dry-season. We evaluated plasma osmolality and innate immune function (agglutination, lysis, and bacterial-killing ability) and found that increased osmolality, whether manipulated in the laboratory or as a result of natural water limitation, resulted in enhanced aspects of innate immune performance. Counter-intuitively, snakes in the wild became more hydrated as the dry season progressed, suggesting the dehydrated snakes move to water sources periodically to rehydrate. Comparing our data with those from previous studies, we suspect species ergence in the level of dehydration (i.e., hyperosmolality) that triggers enhanced immune capabilities.

Effect of soil moisture on yolk and fat distribution in hatchling lizards from natural nests

Publisher: Elsevier BV

Date: 1991

DOI: 10.1016/0300-9629(91)90226-3

Environmental resistance and habitat quality influence dispersal of the saltwater crocodile

Publisher: Wiley

Date: 17-12-2022

DOI: 10.1111/MEC.16310

Abstract: Landscape genetics commonly focuses on the effects of environmental resistance on animal dispersal patterns, but there is an emerging focus on testing environmental effects on emigration and settlement choices. In this study, we used landscape genetics approaches to quantify dispersal patterns in the world's largest crocodilian, the saltwater crocodile ( Crocodylus porosus ), and demonstrated environmental influences on three processes that comprise dispersal: emigration, movement and settlement. We found that both environmental resistance and properties of the source and destination catchments (proportion of breeding habitat) were important factors influencing observed dispersal events. Our habitat quality variables related to hypotheses about resource competition and represented the ratio of breeding habitat (which limits carrying capacity), suggesting that competition for habitat influences emigration and settlement choices, together with the strong effect of environmental resistance to movement (where high‐quality habitat was associated with greatest environmental permeability). Approximately 42% of crocodiles were migrants from populations other than their s ling locations and some outstandingly productive populations had a much higher proportion of emigration rather than immigration. The distance most commonly travelled between source and destination was 150–200 km although a few travelled much longer distances, up to 600–700 km. Given the extensive dispersal range, in idual catchments or hydrographic regions that combine two or three adjacent catchments are an appropriate scale for population management.

The best time of day to monitor and manipulate weaver ant colonies in biological control

Publisher: Wiley

Date: 08-07-2011

DOI: 10.1111/J.1439-0418.2011.01651.X

Abstract: The weaver ant, Oecophylla smaragdina (Hymenoptera: Formicidae), is a successful predator and repellent of a range of insect pests of many economically important crops and forest trees. To use the ant as a biocontrol agent, extension officers and farmers need to know the best time of day to identify and transplant the ant colonies and to measure the abundance of the ant. To answer these questions, it is important to know about ant activity over a 24‐h period at the colony level. Ant activities of three weaver ant colonies on the Tiwi c us of Charles Darwin University, Darwin, were measured in both dry and wet seasons in 1997 and 1998. The activity patterns on three types of ant trails showed that ants were least active between the hours of 10:30 and 14:00, and their activity peaked between 16:00 and 21:00 h. There was also a smaller activity peak from 8:00 to 9:00 h. The best time of day to identify ant colonies and to measure ant abundance is from 16:00 to 21:00 h (late afternoon to dusk). The best time to transplant weaver ant colonies is between 10:30 and 14:00 h (midday).

Physiological consequences of nighttime temperature for a tropical, herbivorous lizard (Cyclura nubila)

Publisher: Canadian Science Publishing

Date: 04-1986

DOI: 10.1139/Z86-125

Abstract: Hatchling Cuban iguanas (Cyclura nubila) were reared for 38 weeks under three experimental conditions: nighttime temperatures of 15, 25, and 35 °C. All groups experienced a temperature of 35 °C during the day, and all were given food and water ad libitum. Growth rate (in terms of mass and length) increased with increasing nighttime temperature. The iguanas held at constant 35 °C were also more robust (defined as mass/length) this difference was not explained by the amount of fat. Passage time of food through the gut was shorter for the constant temperature group, which also consumed more food per day. There was no difference in digestive efficiency among groups, and the differences in growth rates were a result of the differences in food consumption. Constant temperature was apparently not detrimental for this tropical, herbivorous lizard. More data are required before useful generalizations concerning voluntary hypothermia in reptiles can be made.

Changes in body fluids of the cocooning fossorial frog Cyclorana australis in a seasonally dry environment

Publisher: Elsevier BV

Date: 11-2011

DOI: 10.1016/J.CBPA.2011.06.028

Abstract: We investigated changes in the lymph (equivalent to plasma) and urine of the cocooning frog Cyclorana australis during the dry season in monsoonal northern Australia. Frogs in moist soil for two days were fully hydrated (lymph 220 mOsm kg(-1), urine 49 mOsm kg(-1)). From five weeks onwards the soil was dry (matric potential <-8000 kPa). Aestivating frogs at three and five months formed cocoons in shallow (<20 cm) burrows and retained bladder fluid (25-80% of standard mass). After three months, urine but not lymph osmolality was elevated. After five months, lymph (314 mOsm kg(-1)) and urine (294 mOsm kg(-1)) osmolality and urea concentrations were elevated. Urea was a major contributing osmolyte in urine and accumulated in lymph after five months. Lymph sodium concentration did not change with time, whereas potassium increased in urine after five months. Active animals had moderate lymph osmolality (252 mOsm kg(-1)), but urea concentrations remained low. Urine was highly variable in active frogs, suggesting that they tolerate variation in hydration state. Despite prolonged periods in dry soil, osmolality increase in C. australis was not severe. Aestivation in a cocoon facilitates survival in shallow burrows, but such a strategy may only be effective in environments with seasonally reliable rainfall.

Microclimatic Conditions in Nests of the Cuban Iguana (Cyclura nubila)

Publisher: JSTOR

Date: 09-1991

DOI: 10.2307/2388206

Do Weaver Ant (Hymenoptera: Formicidae) Marks Affect Mango Internal Quality and Storage Life?

Publisher: Oxford University Press (OUP)

Date: 02-2013

DOI: 10.1603/EC12162

Abstract: In implementing the integrated pest management mango (Mangifera indica L.) program using weaver ants (Oecophylla smaragdina F.) as a major component in the Northern Territory of Australia, we received a number of questions from farmers and extension officers asking whether weaver ant marks reduce internal fruit quality and induce fruit rot, which is economically important. However, this issue has not been investigated. Soluble sugar content in fruits with and without weaver ant marks and observations on the storage of fruits with the ant marks were recorded in 2002 and 2003. The sugar contents were, in general, higher on the side of the fruit with a relatively large area of ant marks than on the side with a smaller area of ant marks, irrespective of whether fruits were exposed to the sun or not. The field experiment showed that sugar content was generally higher in the treatment with weaver ants plus soft chemicals than in the insecticide treatment. For the storage of fruits bearing weaver ant marks, no signs of diffuse rot from any ant marks were observed, but fruit skin without the ant marks developed a considerable number of dark open lenticels, most of which developed to rot marks and patches. These results suggest that weaver ant marks are positively correlated with internal fruit quality, do not induce fruit rot and can be used as an indicator of better fruit quality and safety.

Biological control of the fruit‐spotting bug Amblypelta lutescens using weaver ants Oecophylla smaragdina on African mahoganies in Australia

Publisher: Wiley

Date: 09-07-2012

DOI: 10.1111/J.1461-9563.2012.00584.X

Seasonal Changes in Thermoregulation by the Frillneck Lizard, Chlamydosaurus Kingii, in Tropical Australia

Publisher: Wiley

Date: 1995

DOI: 10.2307/1940636

Temperature rise and parasitic infection interact to increase the impact of an invasive species

Publisher: Elsevier BV

Date: 04-2017

DOI: 10.1016/J.IJPARA.2016.12.004

Abstract: Invasive species often detrimentally impact native biota, e.g. through predation, but predicting such impacts is difficult due to multiple and perhaps interacting abiotic and biotic context dependencies. Higher mean and peak temperatures, together with parasites, might influence the impact of predatory invasive host species additively, synergistically or antagonistically. Here, we apply the comparative functional response methodology (relationship between resource consumption rate and resource supply) in one experiment and conduct a second scaled-up mesocosm experiment to assess any differential predatory impacts of the freshwater invasive hipod Gammarus pulex, when uninfected and infected with the acanthocephalan Echinorhynchus truttae, at three temperatures representative of current and future climate. In idual G. pulex showed Type II predatory functional responses. In both experiments, infection was associated with higher maximum feeding rates, which also increased with increasing temperatures. Additionally, infection interacted with higher temperatures to synergistically elevate functional responses and feeding rates. Parasitic infection also generally increased Q

Thermal preferences of hatchling saltwater crocodiles (Crocodylus porosus) in response to time of day, social aggregation and feeding

Publisher: Elsevier BV

Date: 12-2012

DOI: 10.1016/J.JTHERBIO.2012.08.003

BIOLOGICAL CONTROL OF AMBLYPELTA SPP (HEMIPTERA: COREIDAE) USING OECOPHYLLA SMARAGDINA (HYMENOPTERA: FORMICIDAE) - PROGRESS, PROSPECTS AND CHALLENGES

Publisher: International Society for Horticultural Science (ISHS)

Date: 04-2002

DOI: 10.17660/ACTAHORTIC.2002.575.57

Underwater Nesting by the Tropical Fresh-Water Turtle, Chelodina-Rugosa (Testudinata, Chelidae)

Publisher: CSIRO Publishing

Date: 1993

DOI: 10.1071/ZO9930047

Abstract: Nests of the northern long-necked turtle, Chelodina rugosa, were located by surgically implanting radio-transmitters in the oviducts of gravid females so that the transmitters were deposited in the nest with the eggs. Nests are excavated in soft substrate under shallow water in the littoral zone of seasonally flooded billabongs during the wet and early dry season. Embryonic development remains arrested until floodwaters recede in the dry season and the ground dries. Hatchling emergence presumably coincides with heavy rain or flooding at the beginning of the following wet season.

Ecological patterns in the skin microbiota of frogs from tropical Australia

Publisher: Wiley

Date: 27-09-2018

DOI: 10.1002/ECE3.4518

Seasonal space use and habitat selection in magpie geese

Publisher: Wiley

Date: 05-07-2022

DOI: 10.1002/JWMG.22289

Abstract: Negative interactions between waterbirds and people are increasing. Waterbirds feeding on agricultural crops cause significant losses to farmers worldwide, but so far most research to address these conflicts has been conducted on migratory species in the temperate northern hemisphere. We investigated the space use and habitat selection of the magpie goose ( Anseranas semipalmata ), a taxonomically distinct waterbird endemic to Australia and southern Papua New Guinea. In tropical northern Australia, magpie geese are protected but are increasingly persecuted by farmers to protect crops during the late dry–early wet season (~Sep–Jan), a bottleneck of natural resources for waterbirds in the monsoonal tropics. Using satellite telemetry of 38 geese spread across 3 seasons (2016–2017, 2017–2018, 2018–2019), we evaluated daily and seasonal space use, in idual site fidelity, and habitat selection to determine the extent of use of agricultural fields by geese, and the spatiotemporal scales at which management should be undertaken. Geese used relatively small daily areas ( x̄ = 8.2 km 2 ) consistently throughout the late dry–early wet season, and repeatedly used agricultural fields, forested bushlands, and local wetlands. Geese used comparatively large seasonal areas ( x̄ = 219.5 km 2 ) encompassing several agricultural areas, and had a low mean overlap between successive weekly core activity areas, indicating that site fidelity rapidly weakened over time. These results suggest that farm‐scale ( ha) management of geese is unlikely to be effective because hazed in iduals are likely to be replaced soon afterwards. Instead, our findings suggest that goose management should be coordinated strategically at the local (~1,000 ha), or regional (~100,000 ha) scale. Farm‐level management would likely be more effective if implemented in conjunction with the creation of regional sanctuaries where geese could rest and potentially feed undisturbed away from farms. Our findings can be used by wildlife managers for optimizing the location of such sanctuaries and highlight the necessity for management to be adaptive given the opportunistic nature of the species.

Thermal and hydric implications of diurnal activity by a small tropical frog during the dry season

Publisher: Wiley

Date: 04-06-2012

DOI: 10.1111/J.1442-9993.2012.02416.X

Born to be bad: agonistic behaviour in hatchling saltwater crocodiles (Crocodylus porosus)

Publisher: Brill

Date: 2013

DOI: 10.1163/1568539X-00003078

Removing the rubbish: frogs eliminate foreign objects from the body cavity through the bladder

Publisher: The Royal Society

Date: 08-12-2010

DOI: 10.1098/RSBL.2010.0877

Abstract: During the course of a telemetry study on three species of Australian frogs ( Litoria caerulea, Litoria dahlii and Cyclorana australis ), we found that many of the surgically implanted transmitters had migrated into the bladder. We subsequently implanted small beads into L. caerulea and they were expelled from the body in 10–23 days. Beads implanted into cane toads ( Rhinella marina ) to document the process were either expelled or were enveloped into the bladder. This appears to be a unique pathway for expulsion of foreign objects from the body, and suggests that caution should be employed in telemetry studies when interpreting the separation of some animals from their transmitters as a mortality event.

Pollinator sharing by the sexually deceptive Green-comb Spider Orchids, Caladenia phaeoclavia, C. parva and C. villosissima (Orchidaceae: Caladeniinae): taxonomic considerations

Publisher: Royal Botanical Gardens and Domain Trust

Date: 22-09-2015

DOI: 10.7751/TELOPEA8762

Abstract: Sexually deceptive orchids are pollinated when male insects perform mating behaviours on the female-mimicking labellum. Such orchids are characterised by extreme pollinator specificity, having only one, or occasionally a few, closely related insect species as pollen vectors. Extreme pollinator specificity may confer complete prezygotic reproductive isolation, thereby avoiding gene flow across species boundaries in the absence of postzygotic barriers. Pollinator specificity is underpinned by precise mimicry of pollen vector sex pheromones. Rapid speciation in sexually deceptive orchid lineages is driven by small changes in allomone chemistry leading to switching of pollinators usually within the same or closely related insect lineages. Such rapid speciation may result in complexes of morphologically and genetically similar cryptic species that present taxonomic challenges. Species boundaries in sexually deceptive orchids are defined by differences in allomone chemistry and are detectable in nature by their specific pollinators, irrespective of minimal morphological or genetic ergence. Conversely, pollinator specificity in sexually deceptive orchids can help to identify ex les of taxonomic over-splitting where complexes of morphologically variable orchid species are shown to share the same pollinator species. In this paper three sexually deceptive morphospecies in the Greencomb Spider Orchid complex, Caladenia parva G.W. Carr, C. phaeoclavia D.L. Jones and C. villosissima G.W. Carr, are shown to share the same thynnid wasp pollen vector, Lophocheilus anilitatus (Smith). The three orchids are closely similar morphologically, are likely to be monophyletic and are considered to be the same biological species. However, phylogenetic analysis is needed to confirm their monophyly, and possible polyploidy in C. villosissima may confer postzygotic reproductive isolation allowing it to share pollinators with C. phaeoclavia and C. parva without hybridizing. It is concluded that pollinator specificity has an important role in identifying species boundaries in complexes of cryptic species, but phylogenetic analysis and possible postzygotic isolating mechanisms should be investigated where pollinator sharing is identified among morphospecies before concluding they are monospecific.

Androgen Concentrations and Behavior of Frillneck Lizards (Chlamydosaurus kingii)

Publisher: JSTOR

Date: 03-1999

DOI: 10.2307/1565537

Water flux in the Australian treefrog Litoria caerulea under natural and semi-natural conditions

Publisher: Brill

Date: 1994

DOI: 10.1163/156853894X00434

A Systematic Review of Behavioral Interventions to Decrease Opioid Prescribing After Surgery.

Publisher: Ovid Technologies (Wolters Kluwer Health)

Date: 02-2019

DOI: 10.1097/SLA.0000000000003483

Carbon dioxide concentrations in the nests of the mud‐dwelling mangrove ant Polyrhachis sokolova Forel (Hymenoptera: Formicidae)

Publisher: Wiley

Date: 10-2003

DOI: 10.1046/J.1440-6055.2003.00372.X

Cane toads (Rhinella marina) rely on water access, not drought tolerance, to invade xeric Australian environments

Publisher: Springer Science and Business Media LLC

Date: 08-12-2019

DOI: 10.1007/S00442-018-4321-1

Abstract: The invasion of habitats with novel environmental challenges may require physiological tolerances not seen in conspecifics from the native range. We used a combination of field and laboratory-based experiments to assess physiological tolerance to limited water access at four sites distributed across the historical invasion path of cane toads (Rhinella marina) in Australia that, from east to west, alternated between mesic and seasonally xeric habitats. Toads from all locations were well hydrated at the time of capture. However, experimental dehydration caused greater mass loss, higher plasma osmolality, and inhibition of lytic ability in toads from xeric compared to mesic locations. These results suggest somewhat surprisingly that toads from xeric environments are physiologically more vulnerable to water loss. In contrast, bactericidal ability was not sensitive to hydric state and was greater in toads from eastern (long-colonized) areas. Similar patterns in lytic ability in hydrated toads and agglutination ability in wild toads suggest that toads along the invasion front face a tradeoff between enhanced dispersal ability and physiological responses to dehydration. The ability of this invasive species to spread into drier environments may be underpinned by a combination of phenotypic plasticity and evolved (heritable) traits.

Seasonal water loss of the lizard Lophognathus temporalis in the wet-dry tropics of northern Australia

Publisher: Brill

Date: 1999

DOI: 10.1163/156853899X00213

Skin resistance to water gain and loss has changed in cane toads (Rhinella marina) during their Australian invasion

Publisher: Wiley

Date: 11-10-2020

DOI: 10.1002/ECE3.6895

First line of defence

Publisher: Elsevier BV

Date: 04-2021

DOI: 10.1016/J.IJPPAW.2021.02.014

How many queens are there in mature colonies of the green ant, Oecophylla smaragdina (Fabricius)?

Publisher: Wiley

Date: 08-1998

DOI: 10.1111/J.1440-6055.1998.TB01579.X

Alligators and Crocodiles Have High Paracellular Absorption of Nutrients, but Differ in Digestive Morphology and Physiology

Publisher: Oxford University Press (OUP)

Date: 09-06-2015

DOI: 10.1093/ICB/ICV060

Abstract: Much of what is known about crocodilian nutrition and growth has come from animals propagated in captivity, but captive animals from the families Crocodilidae and Alligatoridae respond differently to similar diets. Since there are few comparative studies of crocodilian digestive physiology to help explain these differences, we investigated young Alligator mississippiensis and Crocodylus porosus in terms of (1) gross and microscopic morphology of the intestine, (2) activity of the membrane-bound digestive enzymes aminopeptidase-N, maltase, and sucrase, and (3) nutrient absorption by carrier-mediated and paracellular pathways. We also measured gut morphology of animals over a larger range of body sizes. The two species showed different allometry of length and mass of the gut, with A. mississippiensis having a steeper increase in intestinal mass with body size, and C. porosus having a steeper increase in intestinal length with body size. Both species showed similar patterns of magnification of the intestinal surface area, with decreasing magnification from the proximal to distal ends of the intestine. Although A. mississippiensis had significantly greater surface-area magnification overall, a compensating significant difference in gut length between species meant that total surface area of the intestine was not significantly different from that of C. porosus. The species differed in enzyme activities, with A. mississippiensis having significantly greater ability to digest carbohydrates relative to protein than did C. porosus. These differences in enzyme activity may help explain the differences in performance between the crocodilian families when on artificial diets. Both A. mississippiensis and C. porosus showed high absorption of 3-O methyl d-glucose (absorbed via both carrier-mediated and paracellular transport), as expected. Both species also showed surprisingly high levels of l-glucose-uptake (absorbed paracellularly), with fractional absorptions as high as those previously seen only in small birds and bats. Analyses of absorption rates suggested a relatively high proportional contribution of paracellular (i.e., non-mediated) uptake to total uptake of nutrients in both species. Because we measured juveniles, and most paracellular studies to date have been on adults, it is unclear whether high paracellular absorption is generally high within crocodilians or whether these high values are specific to juveniles.

Diet of Amazon river turtles (Podocnemididae): a review of the effects of body size, phylogeny, season and habitat

Publisher: Elsevier BV

Date: 02-2017

DOI: 10.1016/J.ZOOL.2016.07.003

Abstract: Amazon rivers can be ided into three groups (black, white and clear waters) according to the origin of their sediment, dissolved nutrient content, and vegetation. White water rivers have high sediment loads and primary productivity, with abundant aquatic and terrestrial plant life. In contrast, black water rivers are acid and nutrient-poor, with infertile floodplains that support plant species exceptionally rich in secondary chemical defences against herbivory. In this study, we reviewed available information on the diet of Amazon sideneck river turtles (Family Podocnemididae). Our aim was to test the relationship between water type and diet of podocnemidids. We also took into account the effects of season, size, age, sex and phylogeny. Based on our review, turtles of this family are primarily herbivorous but opportunistic, consuming from 46 to 99% (percent volume) of vegetable matter depending on species, sex, season and location. There was no significant correlation between the maximum carapace size of a species and vegetable matter consumed. When the available information on diet, size and habitat was arranged on the podocnemidid phylogeny, no obvious evolutionary trend was evident. The physicochemical properties of the inhabited water type indirectly influence the average volume of total vegetable matter consumed. Species with no specialised stomach adaptations for herbivory consumed smaller amounts of hard to digest vegetable matter (i.e. leaves, shoots and stems). We propose that turtles with specialized digestive tracts may have an advantage in black water rivers where plant chemical defences are more common. Despite limitations of the published data our review highlights the overall pattern of diet in the Podocnemididae and flags areas where more studies are needed.

The effect of the green ant, Oecophylla smaragdina (Hymenoptera: Formicidae), on insect pests of cashew trees in Australia

Publisher: Cambridge University Press (CUP)

Date: 06-1995

DOI: 10.1017/S0007485300034374

Abstract: The influence of green ants, Oecophylla smaragdina (Fabricius), on insect pests of cashew, Anacardium occidentale Linnaeus, in tropical northern Australia was investigated using field surveys and field observations. Oecophylla smaragdina was abundant in the native vegetation of the area, and it was a dominant predator when found in cashew plantations. Oecophylla smaragdina significantly reduced the numbers of the four most important species of insect pests ( Helopeltis pernicialis Stonedahl, Malipatil & Houston, Penicillaria jocosatrix (Guenée), Amblypelta lutescens (Distant) and Anigraea ochrobasis H son) on cashew trees, and trees with higher numbers of O. smaragdina produced higher quality nuts than trees with fewer numbers of O. smaragdina . Other ant species also reduced pest numbers, but not as much as O. smaragdina . The possibility of using O. smaragdina to control insect pests of cashew in the future is discussed.

Scaling of standard metabolic rate in estuarine crocodiles Crocodylus porosus

Publisher: Springer Science and Business Media LLC

Date: 13-12-2012

DOI: 10.1007/S00360-012-0732-1

Abstract: Standard metabolic rate (SMR, ml O2 min(-1)) of captive Crocodylus porosus at 30 °C scales with body mass (kg) according to the equation, SMR = 1.01 M(0.829), in animals ranging in body mass of 3.3 orders of magnitude (0.19-389 kg). The exponent is significantly higher than 0.75, so does not conform to quarter-power scaling theory, but rather is likely an emergent property with no single explanation. SMR at 1 kg body mass is similar to the literature for C. porosus and for alligators. The high exponent is not related to feeding, growth, or obesity of captive animals. The log-transformed data appear slightly curved, mainly because SMR is somewhat low in many of the largest animals (291-389 kg). A 3-parameter model is scarcely different from the linear one, but reveals a declining exponent between 0.862 and 0.798. A non-linear model on arithmetic axes overestimates SMR in 70% of the smallest animals and does not satisfactorily represent the data.

The effect of colony isolation of the predacious ant, Oecophylla smaragdina (F.) (Hymenoptera: Formicidae), on protection of cashew plantations from insect pests

Publisher: Informa UK Limited

Date: 1999

DOI: 10.1080/096708799227789

Partitioning of Respiration between the Gills and Air‐Breathing Organ in Response to Aquatic Hypoxia and Exercise in the Pacific Tarpon,Megalops cyprinoides

Publisher: University of Chicago Press

Date: 09-2004

DOI: 10.1086/422056

Abstract: The evolution of air-breathing organs (ABOs) is associated not only with hypoxic environments but also with activity. This investigation examines the effects of hypoxia and exercise on the partitioning of aquatic and aerial oxygen uptake in the Pacific tarpon. The two-species cosmopolitan genus Megalops is unique among teleosts in using swim bladder ABOs in the pelagic marine environment. Small fish (58-620 g) were swum at two sustainable speeds in a circulating flume respirometer in which dissolved oxygen was controlled. For fish swimming at 0.11 m s(-1) in normoxia (Po2 = 21 kPa), there was practically no air breathing, and gill oxygen uptake was 1.53 mL kg(-0.67) min(-1). Air breathing occurred at 0.5 breaths min(-1) in hypoxia (8 kPa) at this speed, when the gills and ABOs accounted for 0.71 and 0.57 mL kg(-0.67) min(-1), respectively. At 0.22 m s(-1) in normoxia, breathing occurred at 0.1 breaths min(-1), and gill and ABO oxygen uptake were 2.08 and 0.08 mL kg(-0.67) min(-1), respectively. In hypoxia and 0.22 m s(-1), breathing increased to 0.6 breaths min(-1), and gill and ABO oxygen uptake were 1.39 and 1.28 mL kg(-0.67) min(-1), respectively. Aquatic hypoxia was therefore the primary stimulus for air breathing under the limited conditions of this study, but exercise augmented oxygen uptake by the ABOs, particularly in hypoxic water.

Physiological consequences of filarial parasites in the frillneck lizard, Chlamydosaurus kingii, in northern Australia

Publisher: Canadian Science Publishing

Date: 12-1995

DOI: 10.1139/Z95-272

Abstract: Frillneck lizards (Chlamydosaurus kingii) in northern Australia are frequently infected by a mosquito-borne filarial parasite, Oswaldofilaria chlamydosauri. Two sites were studied and the parasite was found to be common at one but absent at the other. At the site where the parasite was present, larger lizards had a higher prevalence of infection. The number of microfilariae in the blood of the lizards was not related to blood hematocrit or hemoglobin concentration. An index of body condition was not related to the presence or number of microfilariae in the blood. Maximum rates of oxygen consumption were measured by running the lizards on a treadmill and neither the presence nor the number of microfilariae was significantly related to aerobic capacity. We also analyzed the blood and physiological parameters with respect to snout–vent length (as an indication of age) to test for consequences of chronic infection, but we found no significant relationships. Although only a few physiological parameters have been examined, the available evidence does not indicate any detrimental effects of the filarial worms on the lizards in this host–parasite association.

Cocoon and Epidermis of AustralianCycloranaFrogs Differ in Composition of Lipid Classes That Affect Water Loss

Publisher: University of Chicago Press

Date: 2012

DOI: 10.1086/663695

Abstract: For hibians to survive in environments that experience annual droughts, they must minimize evaporative water loss. One genus of Australian hylid frogs, Cyclorana, prevents desiccation by burrowing in the soil and forming cocoons composed of alternating layers of shed epidermis and glandular secretions. Previous data are inconclusive about the role that lipids play in reducing evaporative water loss through skin (cutaneous water loss [CWL]) when Cyclorana spp. are within cocoons. In this study, we measured CWL and lipids in the epidermis and in cocoons of five species of Cyclorana. CWL was significantly lower in frogs within cocoons than in frogs without cocoons. Surface-area-specific CWL for the three small species was significantly higher than that of the two larger species of Cyclorana, but this difference was not apparent in frogs within cocoons. Although lipids were responsible for more of the dry mass of the epidermis (approximately 20%) than of the cocoons (approximately 7%) we found that cerebrosides and ceramides, two polar lipid classes, were almost exclusively found in cocoons. This suggests that these lipid classes are in the glandular secretions rather than in the epidermis. Because these polar lipids are the types that reduce water loss in birds (cerebrosides and ceramides) and mammals (ceramides), we conclude that they are important not only for holding together the shed layers of skin but also for contributing to the barrier against water loss.

Thermoregulation by the spotted tree monitor, Varanus scalaris, in the seasonal tropics of Australia

Publisher: Elsevier BV

Date: 04-1996

DOI: 10.1016/0306-4565(95)00023-2

Geographic variation in bacterial assemblages on cane toad skin is influenced more by local environments than by evolved changes in host traits

Publisher: The Company of Biologists

Date: 06-02-2023

DOI: 10.1242/BIO.059641

Abstract: Bacterial assemblages on hibian skin may play an important role in protecting hosts against infection. In hosts that occur over a range of environments, geographic variation in composition of bacterial assemblages might be due to direct effects of local factors and/or to evolved characteristics of the host. Invasive cane toads (Rhinella marina) are an ideal candidate to evaluate environmental and genetic mechanisms, because toads have evolved major shifts in physiology, morphology, and behavior during their brief history in Australia. We used s les from free-ranging toads to quantify site-level differences in bacterial assemblages and a common-garden experiment to see if those differences disappeared when toads were raised under standardised conditions at one site. The large differences in bacterial communities on toads from different regions were not seen in offspring raised in a common environment. Relaxing bacterial clustering to operational taxonomic units in place of licon sequence variants likewise revealed high similarity among bacterial assemblages on toads in the common-garden study, and with free-ranging toads captured nearby. Thus, the marked geographic ergence in bacterial assemblages on wild-caught cane toads across their Australian invasion appears to result primarily from local environmental effects rather than evolved shifts in the host.

Mound Characteristics and Behaviour of the Orange-footed Scrubfowl in the Seasonal Tropics of Australia

Publisher: Informa UK Limited

Date: 03-2000

DOI: 10.1071/MU9853

Effect of diet on nitrogenous wastes of the iguana, Cyclura nubila

Publisher: Elsevier BV

Date: 1986

DOI: 10.1016/0300-9629(86)90291-4

Confirmation of the Hybrid Origin of Chiloglottis × pescottiana (Orchidaceae: Diurideae). I. Genetic and Morphometric Evidence

Publisher: CSIRO Publishing

Date: 1997

DOI: 10.1071/BT96081

Abstract: Pollination by sexual deception in orchids is characterised by a high degree of pollinator specificity, which may account for the rarity of natural hybrids within the group. Only one such hybrid has been formally recognised in Australia, Chiloglottis × pescottiana R.S.Rogers, which has intermediate floral morphology between its putative parents, C. valida D.L.Jones and C. trapeziformis Fitzg. In this paper, genetic and morphometric analyses confirm the hybrid origin of this taxon. Allozyme analysis of C. trapeziformis and C. valida revealed fixed allelic differences at four ‘diagnostic’ loci and significant frequency differences at three other loci. In all cases, C. × pescottiana exhibited fixed heterozygosity at the diagnostic loci. Multidimensional scaling of both the genetic data and seven morphometric traits revealed distinct clusters of C. trapeziformis and C. valida while C. × pescottiana formed an intermediate cluster between the two parents. To test for genetic compatibility between C. trapeziformis, C. valida and C. × pescottiana, a series of reciprocal artificial crosses were performed. In all cases, the percentage of capsules formed was at least as great for between-species crosses as for within-species selfs and crosses (range 75–100%). No significant differences in the percentage of seed with normal embryos was detected between self- and cross-pollinations within C. trapeziformis (range 77–81%), C. valida (range 59–74%) and C. × pescottiana (range 30–51%), but the percentage of normal embryos was notably lower in C. × pescottiana. The cross C. trapeziformis female by C. valida male produced significantly more normal embryos (90%) compared with the reverse cross (46%). Artificial backcrosses of C. × pescottiana to C. valida and C. trapeziformis had lower percentages of normal embryos when C. × pescottiana was the pollen donor (39–43%) rather than recipient (62–68%), suggesting reduced pollen viability in the latter taxon. The size of F2 embryos in C. × pescottiana seed capsules was smaller than the embryos of both C. valida and C. trapeziformis. Despite confirmation of hybridisation, little evidence for backcrossing was found. Thus, while the specific pollinator relationships may occasionally break down in these sexually deceptive orchids, reduced viability of hybrid pollen and F2 seed, and inefficient pollination of the hybrid, may minimise introgression. It is concluded from the available evidence that hybridisation has not been a major evolutionary factor in the ersification of sexual deception worldwide.

The thermal dependency of locomotor performance evolves rapidly within an invasive species

Publisher: Wiley

Date: 02-04-2018

DOI: 10.1002/ECE3.3996

Tail morphology related to habitat of varanid lizards and some other reptiles

Publisher: Brill

Date: 1996

DOI: 10.1163/156853896X00162

Abstract: Tail shape, length and texture were recorded from 28 species of varanid lizards as well as several other reptiles that were known to be either semi-aquatic or arboreal. The varanids were described with respect to their tail characteristics and we then looked for relationships between tail characteristics and what is known about the habitats and lifestyles of the species. Semi-aquatic species of all sizes and phylogenetic groups have laterally compressed tails with a tall "fin" comprising the dorsal one-third of the tail. The tails of the large non-aquatic varanids are laterally compressed with a coarse texture. The smaller species in the subgenus Odatria have more erse tails, and the tail characteristics generally correspond to habitats and lifestyles. The terrestrial species that live under rocks on the soil surface have very coarse, spinous tails. Saxicolous Odattria have long, smooth tails, and arboreal species have coarse tails.

Physiological ecology of a tropical dragon, Lophognathus temporalis

Publisher: Wiley

Date: 04-1999

DOI: 10.1046/J.1442-9993.1999.241960.X

Temporal and spatial activity of insectivorous bats in arid riparian woodland

Publisher: CSIRO Publishing

Date: 2021

DOI: 10.1071/PC19051

Abstract: Insectivorous bats make a significant contribution to mammalian ersity in central Australia, with 12 known extant species however, little is known about their habitat preferences and how these interact with temporal patterns in their abundance and activity. Although most species forage widely and in a variety of habitats, we expected that woodlands associated with ephemeral rivers would constitute high-value habitat for bats because they provide tree hollows, suitable structural habitat for foraging, and canopies rich in invertebrate biomass. The aim of this research was to establish whether riparian woodlands were a focus of bat activity and to identify patterns in habitat use and whether these changed through time. We investigated the activity of bats in riparian woodlands and neighbouring vegetation over 2 years. Bat activity was higher in riparian woodland than in nearby vegetation, and this difference was most significant during a hot and dry summer. At the species level, body size and foraging guild were important factors explaining differences in activity, with larger ‘open space’ species more active in riparian woodland than adjacent habitat. In contrast, we did not detect significant differences in the activity of smaller vespertilionid species between habitats. Coinciding with patterns in invertebrate activity, bat activity was highest in summer and lowest in winter. Within river channels, canopy cover was important in explaining patterns in bat activity. There was also a significant location effect, with bat activity in some river systems much higher than in others. We propose that this is related to both regional variability in rainfall and productivity, in addition to topography. Our findings demonstrate the importance of riparian woodlands to bats in an arid environment, particularly during low-resource periods, and suggest that bats may be affected by future climate changes and degradation from fire impacts.

Locomotor performance of cane toads differs between native-range and invasive populations

Publisher: The Royal Society

Date: 07-2017

DOI: 10.1098/RSOS.170517

Abstract: Invasive species provide a robust opportunity to evaluate how animals deal with novel environmental challenges. Shifts in locomotor performance—and thus the ability to disperse—(and especially, the degree to which it is constrained by thermal and hydric extremes) are of special importance, because they might affect the rate that an invader can spread. We studied cane toads ( Rhinella marina ) across a broad geographical range: two populations within the species' native range in Brazil, two invasive populations on the island of Hawai'i and eight invasive populations encompassing the eastern, western and southern limits of the toad invasion in Australia. A toad's locomotor performance on a circular raceway was strongly affected by both its temperature and its hydration state, but the nature and magnitude of those constraints differed across populations. In their native range, cane toads exhibited relatively low performance (even under optimal test conditions) and a rapid decrease in performance at lower temperatures and hydration levels. At the other extreme, performance was high in toads from southern Australia, and virtually unaffected by desiccation. Hawai'ian toads broadly resembled their Brazilian conspecifics, plausibly reflecting similar climatic conditions. The invasion of Australia has been accompanied by a dramatic enhancement in the toads' locomotor abilities, and (in some populations) by an ability to maintain locomotor performance even when the animal is cold and/or dehydrated. The geographical ergences in performance among cane toad populations graphically attest to the adaptability of invasive species in the face of novel abiotic challenges.

Seasonal activity and energetics of two species of varanid lizards in tropical Australia

Publisher: Springer Science and Business Media LLC

Date: 1995

DOI: 10.1007/BF00328624

Standard metabolic rate and preferred body temperatures in some Australian pythons

Publisher: CSIRO Publishing

Date: 1998

DOI: 10.1071/ZO98019

Abstract: Pythons have standard metabolic rates and preferred body temperatures that are lower than those of most other reptiles. This study investigated metabolic rates and preferred body temperatures of seven taxa of Australian pythons. We found that Australian pythons have particularly low metabolic rates when compared with other boid snakes, and that the metabolic rates of the pythons did not change either seasonally or on a daily cycle. Preferred body temperatures do vary seasonally in some species but not in others. Across all species and seasons, the preferred body temperature range was only 4.9˚C. The thermal sensitivity (Q10) of oxygen consumption by pythons conformed to the established range of between 2 and 3. Allometric equations for the pooled python data at each of the experimental temperatures gave an equation exponent of 0.72–0.76, which is similar to previously reported values. By having low preferred body temperatures and low metabolic rates, pythons appear to be able to conserve energy while still maintaining a vigilant ‘sit and wait’ predatory existence. These physiological attributes would allow pythons to maximise the time they can spend ‘sitting and waiting’ in the pursuit of prey.

Out of sight or in too deep: Effect of visual barriers and water depth on agonistic behaviour and growth in hatchling saltwater crocodiles (Crocodylus porosus)

Publisher: Elsevier BV

Date: 09-2014

DOI: 10.1016/J.APPLANIM.2014.07.001

Intra- and interspecific agonistic behaviour in hatchling Australian freshwater crocodiles (Crocodylus johnstoni) and saltwater crocodiles (Crocodylus porosus)

Publisher: CSIRO Publishing

Date: 2013

DOI: 10.1071/ZO13035

Abstract: We examined agonistic behaviour in hatchling Australian freshwater crocodiles (Crocodylus johnstoni) at 2 weeks, 13 weeks, and 50 weeks after hatching, and between C. johnstoni and saltwater crocodiles (Crocodylus porosus) at 40–50 weeks of age. Among C. johnstoni, agonistic interactions (15–23 s duration) were well established by two weeks old and typically involved two and occasionally three in iduals, mostly between 17 : 00 and 24 : 00 hours in open-water areas of enclosures. A range of discrete postures, non-contact and contact movements are described. The head is rarely targeted in contact movements with C. johnstoni because they exhibit a unique ‘head raised high’ posture, and engage in ‘push downs’. In contrast with C. porosus of a similar age, agonistic interactions between C. johnstoni were conducted with relatively low intensity and showed limited ontogenetic change there was also no evidence of a dominance hierarchy among hatchlings by 50 weeks of age, when the frequency of agonistic interactions was lowest. Agonistic interactions between C. johnstoni and C. porosus at 40–50 weeks of age were mostly low level, with no real exclusion or dominance observed. However, smaller in iduals of both species moved slowly out of the way when a larger in idual of either species approached. When medium- or high-level interspecific interactions did occur, it was between similar-sized in iduals, and each displayed species-specific behaviours that appeared difficult for contestants to interpret: there was no clear winner or loser. The nature of agonistic interactions between the two species suggests that dominance may be governed more strongly by size rather than by species-specific aggressiveness.

Notes onChelodina mccordi timorensisBiology, Harvest, Current Threats, and Community Perceptions in the Lake Iralalaro Region, Timor-Leste

Publisher: Chelonian Conservation and Biology Journal

Date: 06-2016

DOI: 10.2744/CCB-1138.1

The respiratory system in varanid lizards: determinants of O2 transfer

Publisher: Elsevier BV

Date: 10-2002

DOI: 10.1016/S1095-6433(02)00147-2

Abstract: Varanids in general exhibit greater aerobic capacities than other lizards. In a similar approach to the extensive investigations undertaken in mammals, the respiratory system in varanids is examined in terms of oxygen transfer from the air to the blood during rest and sustained locomotory activity. The parameters controlling the transfer of O(2) through the various steps of the respiratory system are appropriate to meet the maximum demands for oxygen with one possible exception, circulatory convection. Ventilatory convection is maintained during maximal aerobic locomotion ensuring adequate pulmonary ventilation and the protection of alveolar P(O(2)). Little evidence exists to indicate a mechanically imposed constraint to breathe and the possibility of a gular pump acting to assist ventilation, as a general feature of varanids remains to be determined. Alterations in the relative contributions of the ventilation-perfusion ratio, pulmonary diffusion, diffusion equilibrium and right-left shunts preserved the alveolar-arterial P(O(2)) difference, ensuring that arterial oxygenation was maintained. In those species where increases in cardiac output were limited, maximum O(2) transfer was achieved through increased extraction of oxygen at the tissues. Overall, the interrelationship of adjacent steps in the respiratory system ensures that one step cannot become limiting. Compensatory changes occur in various parameters to offset those parameters that are 'limited'. The high aerobic activity of varanid lizards would not be achievable without a compensated circulatory convection.

Effect of housing density on growth, agonistic behaviour, and activity in hatchling saltwater crocodiles (Crocodylus porosus)

Publisher: Elsevier BV

Date: 11-2014

DOI: 10.1016/J.APPLANIM.2016.08.007

Spatial patterns of hypolithic cyanobacterial diversity in Northern Australia

Publisher: Wiley

Date: 31-07-2017

DOI: 10.1002/ECE3.3248

Measuring air temperature in field studies

Publisher: Elsevier BV

Date: 02-1985

DOI: 10.1016/0306-4565(85)90012-9

Pollinator rarity limits reintroduction sites in an endangered sexually deceptive orchid (Caladenia hastata): Implications for plants with specialized pollination systems

Publisher: Oxford University Press (OUP)

Date: 05-2017

DOI: 10.1093/BOTLINNEAN/BOX017

Skin bacterial diversity is higher on lizards than sympatric frogs in tropical Australia

Publisher: PeerJ

Date: 14-11-0008

DOI: 10.7717/PEERJ.5960

Abstract: Animal skin acts as a barrier between the organism and its environment and provides the first line of defense against invading pathogens. Thus, skin surfaces harbor communities of microbes that are interacting with both the host and its environment. Amphibian skin bacteria form distinct communities closely tied to their host species, but few studies have compared bacterial communities between hibians and other, non- hibian sympatric animals. Notably, skin microbes on reptiles have gained little attention. We used next-generation sequencing technology to describe bacterial communities on the skin of three lizard species and compared them to bacteria on six cohabiting frog species in the Northern Territory of Australia. We found bacterial communities had higher richness and ersity on lizards than frogs, with different community composition between reptiles and hibians and among species. Core bacteria on the three lizard species overlapped by over 100 operational taxonomic units. The bacterial communities were similar within species of frogs and lizards, but the communities tended to be more similar between lizard species than between frog species and when comparing lizards with frogs. The erse bacteria found on lizards invites further questions on how and how well reptiles interact with microorganisms through their scaly skin.

Physiological control of water exchange in anurans

Publisher: Wiley

Date: 02-2022

DOI: 10.1002/ECE3.8597

Abstract: Research on water exchange in frogs has historically assumed that blood osmotic potential drives water exchange between a frog and its environment, but here we show that the “seat patch” (the primary site of water exchange in many anurans), or other sites of cutaneous water uptake, act as an anatomic “compartment” with a water potential controlled separately from water potential of the blood, and the water potential of that compartment can be the driver of water exchange between the animal and its environment. We studied six frog species ( Xenopus laevis , Rana pipiens , R . catesbeiana , Bufo boreas , Pseudacris cadaverina , and P . regilla ) differing in ecological relationships to environmental water. We inferred the water potentials of seat patches from water exchanges by frogs in sucrose solutions ranging in water potential from 0 to 1000‐kPa. Terrestrial and arboreal species had seat patch water potentials that were more negative than the water potentials of more aquatic species, and their seat patch water potentials were similar to the water potential of their blood, but the water potentials of venters of the more aquatic species were different from (and less negative than) the water potentials of their blood. These findings indicate that there are physiological mechanisms among frog species that can be used to control water potential at the sites of cutaneous water uptake, and that some frogs may be able to adjust the hydric conductance of their skin when they are absorbing water from very dilute solutions. Largely unexplored mechanisms involving aquaporins are likely responsible for adjustments in hydric conductance, which in turn, allow control of water potential at sites of cutaneous water uptake among species differing in ecological habit and the observed disequilibrium between sites of cutaneous water uptake and blood water potential in more aquatic species.

Thermoregulation by the short-horned lizard (Phrynosoma douglassi) at high elevation

Publisher: Elsevier BV

Date: 12-1998

DOI: 10.1016/S0306-4565(98)00031-X

Pollinator specificity, cryptic species and geographical patterns in pollinator responses to sexually deceptive orchids in the genus Chiloglottis: The Chiloglottis gunnii complex

Publisher: CSIRO Publishing

Date: 2009

DOI: 10.1071/BT08164

Abstract: Australian sexually deceptive orchids are typically highly pollinator specific, each species having a single unique hymenopteran pollinator species. Pollinator specificity in six of the nine described species in the Chiloglottis gunnii Lindl. complex was investigated by using field pollinator-choice tests, with Chiloglottis taxa translocated within and among biogeographical regions. Specific pollinators revealed the existence of five undescribed cryptic taxa in the C. gunnii complex, three within C. pluricallata D.L.Jones and two within C. valida D.L.Jones, in addition to the six described species. Of the 11 Chiloglottis taxa, 10 had a single thynnine-wasp pollinator throughout their sometimes large distributions, whereas one, C. valida, had a second pollinator in parts of its distribution. Eleven pollinators belonged to the genus Neozeleboria and one to Eirone. Pollinator-choice testing showed that cross-attraction of pollinators occurs between three geographically isolated Chiloglottis taxa on the New South Wales (NSW) New England Tableland and taxa in the South Eastern Highlands of NSW and Victoria. The data suggested there is sharing of chemical attractants and supported the recognition of at least five odour types within Chiloglottis, each encompassing one to three orchid taxa and their pollinators. The following two broad generalisations are made: (1) there is no cross-attraction of pollinators among sympatric Chiloglottis species, i.e. sympatric orchid taxa do not share attractant odours and (2) all Chiloglottis species have different specific pollinators, although they may share attractant odours allopatrically. Some 28 thynnine-wasp species were attracted as minor non-pollinating responders to Chiloglottis taxa five of these were pollinators of other Chiloglottis species. These wasps were much more taxonomically erse than the pollinators, belonging to six genera, and suggest that some orchid-odour components are widely shared within the sex pheromones of the Thynninae.

Differences in structure of northern Australian hypolithic communities according to location, rock type, and gross morphology

Publisher: American Institute of Mathematical Sciences (AIMS)

Date: 2018

DOI: 10.3934/MICROBIOL.2018.3.469

Osmotic Balance in the Eggs of the Turtle Chelodina rugosa during Developmental Arrest under Water

Publisher: University of Chicago Press

Date: 05-1997

DOI: 10.1086/639604

Abstract: The tropical Australian turtle Chelodina rugosa normally lays its hard-shelled eggs in mud, under shallow freshwater, during the monsoon season. The eggs undergo developmental arrest until the water recedes and oxygen is able to diffuse into the embryo. This period of arrest can exceed 12 wk without embryonic mortality. To understand how the eggs avoid osmotic absorption of water leading to shell rupture and embryonic death, this study investigates the solute concentrations and volumes of the albumen and yolk compartments during submergence in distilled water. The albumen loses considerable sodium through the shell, particularly during the first week, and its osmotic concentration drops from 234 mmol/kg at laying to about 23 mmol/kg. Meanwhile, water from the albumen slowly moves through the vitelline membrane into the yolk compartment, which enlarges at a constant rate until it approaches the inside of the shell at about 22 wk. Osmotic uptake dilutes yolk solutes, decreasing the osmotic concentration from 281 mmol/kg at laying to 132 mmol/kg at 157 d. Loss of embryonic viability is associated with contact of the vitelline membrane with the inside of the shell. The principal adaptation of this species for protracted developmental arrest under water is a vitelline membrane of such low permeability to water that the expansion of the yolk compartment occurs about 10 times more slowly than in other chelonians.

Energy, water balance and the roost microenvironment in three Australian cave-dwelling bats (Microchiroptera)

Publisher: Springer Science and Business Media LLC

Date: 27-09-2000

DOI: 10.1007/S003600000121

Abstract: The ghost bat, Macroderma gigas, and the orange leaf-nosed bat, Rhinonycteris aurantius, occupy similar ranges across northern Australia and are often found in the same roost caves. Both species are considered rare and vulnerable to further population decline. A third small species, the large bent-wing bat, Miniopterus schreibersii, has a similar body mass to R. aurantius, but has one of the largest ranges of any Australian mammal. In the present study we examine the effect and sensitivity of the animals' roosting microclimates on their energy and water balance. M. schreibersii exhibits a basal metabolic rate about 40% greater than other bats of similar body mass, whereas the other two species are close to predicted levels. R. aurantius shows a decrease in body temperatures below thermoneutrality. R. aurantius has levels of pulmocutaneous water loss among the highest seen for a mammal, and calculations based on nasal tip temperatures suggest that most of this loss is across the skin. Calculated ambient temperatures at which metabolic water production is equal to pulmocutaneous water loss in dry air are -14.7 degrees C for R. aurantius, 9.8 degrees C for M. schreibersii and -0.3 degrees C for M. gigas. Exposing the animals to relative humidities of between 80% and 90% shifted these calculated temperatures to 5.6 degrees C, 25.2 degrees C, and 2.9 degrees C, respectively. For each species the ratio of metabolic water production to evaporative water loss has been treated as a joint function of humidity and ambient temperature. The resulting surface plot shows that under known roosting conditions in caves R. aurantius and M. schreibersii remain in positive water balance, whereas M. gigas does not.

Reproductive success and pollination of the Tuncurry Midge Orchid (Genoplesium littorale) (Orchidaceae) by Chloropid Flies

Publisher: Royal Botanical Gardens and Domain Trust

Date: 17-02-2015

DOI: 10.7751/TELOPEA8127

Abstract: The Midge Orchids (Genoplesium R.Br.) (Orchidaceae) are thought to attract pollinators by nectar reward. All verified records of Genoplesium pollinators are small flies of the families Chloropidae and Milichiidae, suggesting pollinator specificity. We investigated pollination of the Critically Endangered Tuncurry Midge Orchid, Genoplesium littorale D.L.Jones. In common with other Genoplesium species, G. littorale is pollinated exclusively by chloropid flies. Although there is specificity at the pollinator family level, G. littorale is oligophilous, being pollinated by five putative chloropid species in two genera, Conioscinella and Cadrema. Most visitors were female with females greatly predominating among flies bearing pollinaria. Examination of flowers on ten inflorescences showed G. littorale is outcrossing with high pollen vector activity pollinaria had been removed from 71% of post anthesis flowers. A set of criteria for distinguishing outcrossed, autogamous and apomictic flowers based on observations of pollinaria removal, pollination of stigmas and fruit set on in idual flowers ruled out the occurrence of autogamy and apomixis in G. littorale. Fruit set on inflorescences averaged 44% percent prior to seed dispersal and varied significantly among sub-populations. Nectar is produced in the groove of the labellum callus, although flowers emitted no odour detectable by humans. Detailed examination of 29 flowers revealed no chloropid eggs, indicating the pollination syndrome is not brood site mimicry. The absence of strong dung or carrion-like odours also makes sapromyophily unlikely. The Genoplesium pollination syndrome is nectar reward, but may also represent an ex le of ‘kleptomyiophily’, recently described in Aristolochia rotunda. Herbivory reduced reproductive capacity by half overall, varied significantly among sub-populations and may be a significant threatening process for G. littorale. Strategies to reduce herbivory in this critically endangered species should be investigated.

Do weaver ants affect arthropod diversity and the natural‐enemy‐to‐pest ratio in horticultural systems?

Publisher: Wiley

Date: 19-04-2013

DOI: 10.1111/JEN.12058

Metabolic response to feeding and fasting in the water python (Liasis fuscus)

Publisher: CSIRO Publishing

Date: 2001

DOI: 10.1071/ZO01017

Abstract: Compared with other reptiles, pythons have a relatively low standard metabolic rate (SMR) when post-absorptive, but metabolism increases substantially after feeding. This study examined the effects of feeding and fasting on adult and hatchling water pythons (Liasis fuscus). We compared ratios of peak digestive metabolic rate (PDMR) after feeding with the metabolic rate of both post-absorptive (SMR) and fasted water pythons. If metabolic rate of a fasting snake is taken as ‘SMR’, then the ratio PDMR/SMR becomes increasingly exaggerated as fasting continues. After 56 days of fasting in adults, or after 45 days in hatchlings, the metabolic rate of water pythons was significantly lower than that of post-absorptive animals. Peak digestive metabolic rate of post-absorptive adult water pythons was only 6.3–12.0 times SMR, but the ratio was twice that if fasted (metabolically depressed) animals were used to determine the ‘SMR’ denominator. Thus, this ratio should be used with caution. Peak digestive metabolic rate after feeding increased with increasing meal size for meals less than 20% of body mass, but PDMR did not increase for meals between 20% and 39% of body mass for adult water pythons. Similarly, the PDMR did not increase signif icantly between 25% and 50% meal sizes for hatchlings. The digestive physiology of water pythons is apparently better suited to frequent meals of relatively small prey compared with the digestive physiology of some other pythons.

The effects of fire on the frillneck lizard (Chlamydosaurus kingii) in northern Australia

Publisher: Wiley

Date: 12-1996

DOI: 10.1111/J.1442-9993.1996.TB00625.X

Activity and Resting Metabolism of Varanid Lizards Compared With Typical Lizards

Publisher: CSIRO Publishing

Date: 1994

DOI: 10.1071/ZO9940185

Abstract: We examined whether Australian varanids as a group are more aerobic than other lizards. The standard metabolic rate (SMR) and maximal oxygen consumption (V-O2max) were measured for four species of varanid lizards and the skink Tiliqua rugosa at 35 degrees C. These were compared to each other and to the V-O2max of the iguanid lizard Cyclura nubila by analysis of covariance with body mass as a covariate. There were no differences with respect to SMR, but the V-O2max of the lizards fell into three groups: Varanus rosenbergi, V. gouldii and V. panoptes had higher aerobic capacities than V. mertensi and Cyclura nubila, and Tiliqua rugosa had a V-O2max lower than the other species. There is no simple relationship between V-O2max and the time these lizards spend in natural activity. The summer SMRs of V. rosenbergi and T. rugosa were significantly higher than during other seasons. The V-O2max of V. rosenbergi was higher in summer than in other seasons, but T. rugosa showed no seasonal differences in V-O2max. These results indicate that the SMRs of the varanids were similar to those of other lizards, and, despite generalisations in the literature, not all varanid lizards have high aerobic capacities. Varanid lizards may be as physiologically erse as other lizard families.

Good vibrations? Sibling embryos expedite hatching in a turtle

Publisher: Elsevier BV

Date: 03-2012

DOI: 10.1016/J.ANBEHAV.2011.12.006

The Diversity of Nitrogen-Cycling Microbial Genes in a Waste Stabilization Pond Reveals Changes over Space and Time that Is Uncoupled to Changing Nitrogen Chemistry

Publisher: Springer Science and Business Media LLC

Date: 10-11-2020

DOI: 10.1007/S00248-020-01639-X

Abstract: Nitrogen removal is an important process for wastewater ponds prior to effluent release. Bacteria and archaea can drive nitrogen removal if they possess the genes required to metabolize nitrogen. In the tropical savanna of northern Australia, we identified the previously unresolved microbial communities responsible for nitrogen cycling in a multi-pond wastewater stabilization system by measuring genomic DNA and cDNA for the following: nifH (nitrogen fixation) nosZ (denitrification) hzsA (anammox) archaeal AamoA and bacterial BamoA (ammonia oxidation) nxrB (nitrite oxidation) and nrfA (dissimilatory NO 3 reduction to NH 3 ). By collecting 160 DNA and 40 cDNA wastewater s les and measuring nitrogen (N)-cycling genes using a functional gene array, we found that genes from all steps of the N cycle were present and, except for nxrB , were also expressed. As expected, N-cycling communities showed daily, seasonal, and yearly shifts. However, contrary to our prediction, probes from most functional groups, excluding nosZ and AamoA , were different between ponds. Further, different genes that perform the same N-cycling role sometimes had different trends over space and time, resulting in only weak correlations between the different functional communities. Although N-cycling communities were correlated with wastewater nitrogen levels and physico-chemistry, the relationship was not strong enough to reliably predict the presence or ersity of N-cycling microbes. The complex and dynamic response of these genes to other functional groups and the changing physico-chemical environment provides insight into why altering wastewater pond conditions can result an abundance of some gene variants while others are lost.

Stability and predictability of bird assemblages in an arid riparian woodland during contrasting periods of resource availability

Publisher: Wiley

Date: 02-08-2020

DOI: 10.1111/AEC.12933

The weaver ant,Oecophylla smaragdina(Hymenoptera: Formicidae), an effective biological control agent of the red-banded thrips,Selenothrips rubrocinctus(Thysanoptera: Thripidae) in mango

Publisher: Informa UK Limited

Date: 04-2004

DOI: 10.1080/09670870410001658125

The Relationship between Early Growth and Survival of Hatchling Saltwater Crocodiles (Crocodylus porosus) in Captivity

Publisher: Public Library of Science (PLoS)

Date: 24-06-2014

DOI: 10.1371/JOURNAL.PONE.0100276

Ecological Observations on the Spinifex Ant, Ochetellus flavipes (Kirby) (Hymenoptera: Formicidae), of Australia's Northern Arid Zone

Publisher: Wiley

Date: 11-1994

DOI: 10.1111/J.1440-6055.1994.TB01235.X

Physical calculations of resistance to water loss improve predictions of species range models: comment

Publisher: Wiley

Date: 29-09-2017

DOI: 10.1002/ECY.1982

Dental data challenge the ubiquitous presence of Homo in the Cradle of Humankind

Publisher: Proceedings of the National Academy of Sciences

Date: 05-07-2022

DOI: 10.1073/PNAS.2111212119

Abstract: The origins of Homo , as well as the ersity and biogeographic distribution of early Homo species, remain critical outstanding issues in paleoanthropology. Debates about the recognition of early Homo , first appearance dates, and taxonomic ersity within Homo are particularly important for determining the role that southern African taxa may have played in the origins of the genus. The correct identification of Homo remains also has implications for reconstructing phylogenetic relationships between species of Australopithecus and Paranthropus , and the links between early Homo species and Homo erectus . We use microcomputed tomography and landmark-free deformation-based three-dimensional geometric morphometrics to extract taxonomically informative data from the internal structure of postcanine teeth attributed to Early Pleistocene Homo in the southern African hominin-bearing sites of Sterkfontein, Swartkrans, Drimolen, and Kromdraai B. Our results indicate that, from our s le of 23 specimens, only 4 are unambiguously attributed to Homo , 3 of them coming from Swartkrans member 1 (SK 27, SK 847, and SKX 21204) and 1 from Sterkfontein (Sts 9). Three other specimens from Sterkfontein (StW 80 and 81, SE 1508, and StW 669) approximate the Homo condition in terms of overall enamel–dentine junction shape, but retain Australopithecus -like dental traits, and their generic status remains unclear. The other specimens, including SK 15, present a dominant australopith dental signature. In light of these results, previous dietary and ecological interpretations can be reevaluated, showing that the geochemical signal of one tooth from Kromdraai (KB 5223) and two from Swartkrans (SK 96 and SKX 268) is consistent with that of australopiths.

The effect of the thermal environment on the ability of hatchling Galapagos land iguanas to avoid predation during dispersal

Publisher: Springer Science and Business Media LLC

Date: 05-1981

DOI: 10.1007/BF00349191

Seasonal Shifts in Body Temperature and Use of Microhabitats by Galapagos Land Iguanas (Conolophus Pallidus)

Publisher: Wiley

Date: 06-1983

DOI: 10.2307/1939965

Pearl Oyster Bacterial Community Structure Is Governed by Location and Tissue-Type, but Vibrio Species Are Shared Among Oyster Tissues.

Publisher: Frontiers Media SA

Date: 09-08-2021

DOI: 10.3389/FMICB.2021.723649

Abstract: Diseases of bivalves of aquacultural importance, including the valuable Australian silver-lipped pearl oyster ( Pinctada maxima ), have been increasing in frequency and severity. The bivalve microbiome is linked to health and disease dynamics, particularly in oysters, with putative pathogens within the Vibrio genus commonly implicated in oyster diseases. Previous studies have been biased toward the Pacific oyster because of its global dominance in oyster aquaculture, while much less is known about the microbiome of P. maxima . We sought to address this knowledge gap by characterizing the P. maxima bacterial community, and we hypothesized that bacterial community composition, and specifically the occurrence of Vibrio , will vary according to the s led microenvironment. We also predicted that the inside shell swab bacterial composition could represent a source of microbial spillover biofilm into the solid pearl oyster tissues, thus providing a useful predictive s ling environment. We found that there was significant heterogeneity in bacterial composition between different pearl oyster tissues, which is consistent with patterns reported in other bivalve species and supports the hypothesis that each tissue type represents a unique microenvironment for bacterial colonization. We suggest that, based on the strong effect of tissue-type on the pearl oyster bacterial community, future studies should apply caution when attempting to compare microbial patterns from different locations, and when searching for disease agents. The lack of association with water at each farm also supported the unique nature of the microbial communities in oyster tissues. In contrast to the whole bacterial community, there was no significant difference in the Vibrio community among tissue types nor location. These results suggest that Vibrio species are shared among different pearl oyster tissues. In particular, the similarity between the haemolymph, inside shell and solid tissues, suggests that the haemolymph and inside shell environment is a source of microbial spillover into the oyster tissues, and a potentially useful tool for non-destructive routine disease testing and early warning surveillance. These data provide important foundational information for future studies identifying the factors that drive microbial assembly in a valuable aquaculture species.

Implications of pollination by food and sexual deception for pollinator specificity, fruit set, population genetics and conservation of Caladenia (Orchidaceae)

Publisher: CSIRO Publishing

Date: 2009

DOI: 10.1071/BT08154

Abstract: Caladenia is very unusual in that it contains species that attract pollinators by two different strategies, food and sexual deception. Among the sexually deceptive species, baiting for pollinators has shown that within populations orchid species are typically pollinated by a single species of thynnine wasp. However, some wasp species can be pollinators of more than one species of orchid usually when their ranges do not overlap. There is a trend for closely related orchids to exploit wasps from the same genus, with different lineages of orchids often pollinated by different genera. Very little is known about pollination of food-deceptive Caladenia species, although it is evident they attract a suite of generalist food-seeking insects. Food-deceptive species have a higher pollination rate than do sexually deceptive species. Studies of population genetics and pollen movements are few, although they suggest a pattern of fine-scale genetic structuring within populations, owing to predominantly restricted seed dispersal and low genetic differentiation among populations as a consequence of rare long-distance seed-dispersal events. Both evolutionary and ecological research of Caladenia will greatly benefit from a better understanding of the insect species involved in pollination, their ecological requirements and the ecological and genetic consequences of food and sexual deception.

Digestive Efficiency in Some Australian Pythons

Publisher: American Society of Ichthyologists and Herpetologists (ASIH)

Date: 08-2000

DOI: 10.1643/0045-8511(2000)000[0829:DEISAP]2.0.CO;2

Cane toads lack physiological enhancements for dispersal at the invasive front in Northern Australia

Publisher: The Company of Biologists

Date: 02-11-2011

DOI: 10.1242/BIO.2011024

Abstract: Many invasive species have evolved behavioural and morphological characteristics that facilitate their dispersal into new areas, but it is unclear how selection on this level of the phenotype filters through to the underlying physiology. Cane toads have been dispersing westward across northern tropical Australia for more than 70 years. Previous studies of cane toads at the invasive front have identified several behavioural, morphological and locomotory characteristics that have evolved to facilitate dispersal of toads. We assessed a range of physiological characteristics associated with locomotory abilities in toads from the long-established, east coast of Australia, from the invasive front, and from a site in between these locations. We measured time to exhaustion and respiratory gases of toads exercising on a treadmill, time to recovery from exhaustion, blood properties (lactate, haematocrit, haemoglobin, red blood cell count, blood cell volume), and muscle properties associated with locomotion (activities of the enzymes citrate synthase and lactate dehydrogenase, and pH buffering capacity). None of the measured physiological parameters supported the hypothesis that toads from the invasive front possess physiological adaptations that facilitate dispersal compared to toads from areas colonised in the past. The strongest difference among the three groups of toads, time to exhaustion, showed exactly the opposite trend toads from the long-established populations in the east coast had the longest time to exhaustion. Successful colonisers can employ many characteristics to facilitate their dispersal, so the extent to which behaviour, morphology and physiology co-evolve remains an interesting question. However, in the present case at least, behavioural adaptations do not appear to have altered the organism's underlying physiology.

Cutaneous Melanin Density of Caucasians Measured by Spectrophotometry and Risk of Malignant Melanoma, Basal Cell Carcinoma, and Squamous Cell Carcinoma of the Skin

Publisher: Oxford University Press (OUP)

Date: 04-2002

DOI: 10.1093/AJE/155.7.614

Abstract: Recent advances have enabled quite accurate estimation by spectrophotometry of the density of cutaneous melanin. The relation between skin cancers and this objective measure of skin phenotype is examined here. For this purpose, a population-based case-control study of subjects aged 20-59 years of northern European ancestry was conducted in Tasmania, Australia. Cases (n = 244) of cutaneous malignant melanoma during 1998-1999, and a s le of cases of basal cell carcinoma (n = 220) and squamous cell carcinoma (n = 195) of the skin were identified from cancer registrations. Controls (n = 483) were selected from a comprehensive population listing. Melanin at the upper inner arm was estimated from skin reflectance of light of 400 and 420 nm wavelengths. For melanoma, basal cell carcinoma, and squamous cell carcinoma, respectively, the odds ratios comparing the least with the highest of four melanin categories were 6.2 (95% confidence interval (CI): 2.3, 16.6), 6.3 (95% CI: 2.6, 15.1), and 4.2 (95% CI: 1.7, 10.8) for men and 1.9 (95% CI: 1.0, 3.7), 1.4 (95% CI: 0.7, 3.0), and 0.7 (95% CI: 0.3, 1.7) for women. The gender differences were not due to disparities in site of occurrence or (for melanoma) in thickness of the lesion. The authors conclude that, particularly for men, cutaneous melanin density at the upper inner arm is a strong predictor of risk of skin cancer.

Hidden biodiversity: Detection of cryptic Thynnine wasp species using sexually deceptive, female mimicking orchids

Publisher: Museums Victoria

Date: 1997

DOI: 10.24199/J.MMV.1997.56.39

Microbial communities associated with mounds of the Orange-footed scrubfowl Megapodius reinwardt

Publisher: PeerJ

Date: 25-07-2022

DOI: 10.7717/PEERJ.13600

Abstract: Megapodius reinwardt , the orange-footed scrubfowl, belongs to a small family of birds that inhabits the Indo-Australian region. Megapodes are unique in incubating their eggs in mounds using heat from microbial decomposition of organic materials and solar radiation. Little is known about the microorganisms involved in the decomposition of organic matter in mounds. To determine the source of microbes in the mounds, we used 16S and 18S rRNA gene sequencing to characterize the microbial communities of mound soil, adjacent soil and scrubfowl faeces. We found that the microbial communities of scrubfowl faeces were substantially different from those of the mounds and surrounding soils, suggesting that scrubfowls probably do not use their faeces to inoculate their mounds although a few microbial sequence variants were present in both faeces and mound s les. Further, the mound microbial community structure was significantly different to the adjacent soils. For ex le, mounds had a high relative abundance of sequence variants belonging to Thermomonosporaceae , a thermophilic soil bacteria family able to degrade cellulose from plant residues. It is not clear whether members of Thermomonosporaceae disproportionately contribute to the generation of heat in the mound, or whether they simply thrive in the warm mound environment created by the metabolic activity of the mound microbial community. The lack of clarity in the literature between designations of heat-producing (thermogenic) and heat-thriving (thermophilic) microbes poses a challenge to understanding the role of specific bacteria and fungi in incubation.

Don't put all your eggs in one basket – Lessons learned from the largest-scale and longest-term wildlife conservation program in the Amazon Basin

Publisher: Elsevier BV

Date: 10-2019

DOI: 10.1016/J.BIOCON.2019.07.027

Characteristics of hollows and hollow-bearing trees in semi-arid river red gum woodland and potential limitations for hollow-dependent wildlife

Publisher: Wiley

Date: 05-2019

DOI: 10.1111/AEC.12765

Weaver Ant Role in Cashew Orchards in Vietnam

Publisher: Oxford University Press (OUP)

Date: 08-2014

DOI: 10.1603/EC14039

Abstract: Cashew (Anacardium occidentale L.) is a very important source of income for more than 200,000 farmer households in Vietnam. The present cashew productivity in Vietnam is low and unstable, and pest damage is partly responsible for this. Cashew farmers rely on pesticides to minimize the damage, resulting in adverse impacts on farm environment and farmers' health. Weaver ants (Oecophylla spp) are effective biocontrol agents of a range of cashew insect pests in several cashew-growing countries, and these ants are widely distributed in Vietnam. The aim of this study is to evaluate the potential of weaver ants in cashew orchards in Vietnam. Field surveys and field experiment were conducted in five cashew orchards from July 2006 to January 2008 in Binh Phuoc, Dong Nai, and Ba Ria Vung Tau provinces, Vietnam. Based on the field surveys, the most important pests that damage flushing foliar and floral shoots and young cashew fruits and nuts were mosquito bugs, brown shoot borers, blue shoot borers, and fruit-nut borers. The damage caused by each of these pests was significantly lower on trees with weaver ants compared with trees without the ants, showing that the ants were able to keep these pest damages under the control threshold. Regular monitoring of the field experiment showed that weaver ants were similar to insecticides for controlling mosquito bugs, blue shoot borers, fruit-nut borers, leaf rollers, and leaf miners. Aphids did not become major pests in plot with weaver ants. To manage insect pest assemblage in cashew orchards, an integrated pest management using weaver ants as a major component is discussed.

Specific pollinators reveal a cryptic taxon in the bird orchid, Chiloglottis valida sensu lato (Orchidaceae) in south-eastern Australia

Publisher: CSIRO Publishing

Date: 2006

DOI: 10.1071/BT05043

Abstract: Orchid species belonging to the sexual-deception pollination syndrome exhibit highly specific, usually one-to-one, relationships with their pollinators. This specificity is mediated by the orchid’s mimicry of the sex-attractant pheromones emitted by females of the pollinator species. Chiloglottis valida D.Jones sensu lato is a widespread, sexually deceptive, terrestrial orchid found in south-eastern New South Wales, and eastern and southern Victoria from sea level to at least 1600 m in the Australian Alps. Flowers from 38 C. valida s.l. populations from throughout this area were compared in field choice experiments for the specificity of attracted pollinator species. Four potential pollinator wasps in the thynnine genus Neozeleboria Rohwer were attracted. The data demonstrate the existence of two attractant odour types among C. valida s.l. and its pollinators, and support the recognition of two partially sympatric cryptic species in the orchid, each with two potential pollinators. The copheromone pollinator pairs replace each other on the altitudinal gradient, albeit with some overlap. In alpine areas the pollinators of the two cryptic orchid species are themselves sibling species within Neozeleboria monticola Turner s.l. The results indicate that C. aff. valida, the sister species of C. valida s.s., has two geographically replacing pollinators.

The Good, the Bad, and the Ugly: Agonistic Behaviour in Juvenile Crocodilians

Publisher: Public Library of Science (PLoS)

Date: 11-12-2013

DOI: 10.1371/JOURNAL.PONE.0080872

Locating queen ant nests in the green ant, Oecophylla smaragdina (hymenoptera, formicidae)

Publisher: No publisher found

Date: 1998

DOI: 10.1007/S000400050103

Using weaver antsOecophylla smaragdinato control two important pests on African mahoganyKhaya senegalensisin the Northern Territory of Australia

Publisher: Informa UK Limited

Date: 06-2013

DOI: 10.1080/00049158.2013.776938

Thermal Relations of Some Tropical Frogs Along an Altitudinal Gradient

Publisher: JSTOR

Date: 09-1988

DOI: 10.2307/2388239

Energetics and Water Flux in a Semiaquatic Lizard, Varanus mertensi

Publisher: JSTOR

Date: 16-05-1996

DOI: 10.2307/1446851

Estimating clinical stage of amyotrophic lateral sclerosis from the ALS Functional Rating Scale.

Publisher: Informa UK Limited

Date: 10-04-2014

DOI: 10.3109/21678421.2014.897357

Energetic consequences of metabolic depression in tropical and temperate-zone lizards

Publisher: CSIRO Publishing

Date: 1999

DOI: 10.1071/ZO98061

Abstract: One response of ectothermic animals to periods of inactivity is inverse acclimation, or metabolic depression, which results in the conservation of energy. Most studies of metabolic depression and acclimation have involved temperate-zone species, and the information from tropical species has been largely restricted to laboratory studies that failed to demonstrate thermal acclimation of metabolism. Recently, metabolic depression has been shown in several species of reptiles from the wet-dry tropics of northern Australia during the dry season. We review existing data on the energy budgets of temperate and tropical species during periods of inactivity and make calculations of energy saved due to metabolic depression across a range of temperatures. Because tropical species experience relatively high temperatures during periods of inactivity, they have a greater potential for energy savings, any enhancement of their metabolic depression is disproportionately advantageous with respect to energy savings, and in some species metabolic depression is probably essential for survival. Thus, we would expect metabolic depression to be well developed in some tropical reptiles. The lack of thermal acclimation in laboratory studies indicates that environmental parameters other than temperature (such as food or water) may initiate metabolic depression in tropical species. Higher temperatures, however, magnify the energy savings accomplished by metabolic depression.

Distribution of the green ant, Oecophylla smaragdina (F.) (Hymenoptera: Formicidae), in relation to native vegetation and the insect pests in cashew plantations in Australia

Publisher: Informa UK Limited

Date: 1997

DOI: 10.1080/096708797228690

Analysis of the Activity and Energetics of the Lizard Varanus rosenbergi

Publisher: JSTOR

Date: 16-05-1994

DOI: 10.2307/1446978

Thermoregulation of Monitor Lizards in Australia: An Evaluation of Methods in Thermal Biology

Publisher: Wiley

Date: 05-1996

DOI: 10.2307/2963472

Seasonal metabolism of a small, arboreal monitor lizard, Varanus scalaris, in tropical Australia

Publisher: Wiley

Date: 10-1996

DOI: 10.1111/J.1469-7998.1996.TB05293.X

Reduced Rates of Water Loss and Chemical Properties of Skin Secretions of the Frogs Litoria caerulea and Cyclorana australis

Publisher: CSIRO Publishing

Date: 1997

DOI: 10.1071/ZO96046

Abstract: We measured the rates of water loss in two Australian hylid frogs: the arboreal Litoria caerulea and the terrestrial burrowing frog Cyclorana australis. We measured the latter species with and without cocoons. Both species showed reduced rates of water loss compared with ‘typical’ hibians that lose water as if from a free surface. Cocooned C. australis had very low rates of water loss. We examined the chemical composition of skin secretions rinsed (using only high-pure water) from both species and the cocoon material from C. australis. The chemical composition of the material from these three sources was generally similar and consisted of 5–10% neutral lipids and 78–85% proteinaceous material. The fact that the terrestrial species has a high resistance to water loss is unusual given that almost all other known species of non-cocooned frogs with reduced rates of water loss are arboreal. The chemical similarity of the skin secretions and cocoons from this species suggest that the reduced rate of water loss in this species is linked to its ability to form a cocoon. Amino acid composition of the material indicated that a sclerotisation process may occur upon oxidation of the secretions. This would result in a physical barrier to water loss in the cocoons and possibly a thin physical proteinaceous barrier on the skin of both species in the absence of cocoons. We suggest that the high proportion of proteins in the skin secretions cannot be ignored, and that it may, in conjunction with the lipids, produce an effective waterproofing barrier in both species. We suggest that chemical components other than lipids also may be important in frogs from other continents, and complete compositional analyses of frog ‘mucus’ are required before we can fully understand the nature of the mechanisms involved in reduced rates of water loss in hibians with and without cocoons.

Pollinator specificity, floral odour chemistry and the phylogeny of Australian sexually deceptive Chiloglottis orchids: Implications for pollinator-driven speciation

Publisher: Wiley

Date: 07-06-2010

DOI: 10.1111/J.1469-8137.2010.03308.X

Abstract: Featured paper: See Commentary p303

Disease Exposure and Antifungal Bacteria on Skin of Invasive Cane Toads, Australia

Publisher: Centers for Disease Control and Prevention (CDC)

Date: 09-2019

DOI: 10.3201/EID2509.190386

The effect of weaver ants Oecophylla smaragdina on the shoot borer Hypsipyla robusta on African mahoganies in Australia

Publisher: Wiley

Date: 25-01-2011

DOI: 10.1111/J.1461-9563.2010.00514.X

Defining conservation units in a complex of morphologically similar, sexually deceptive, highly endangered orchids

Publisher: Elsevier BV

Date: 06-2014

DOI: 10.1016/J.BIOCON.2014.03.017

Oxygen transport capacity in the air-breathing fish, Megalops cyprinoides: compensations for strenuous exercise

Publisher: Elsevier BV

Date: 2003

DOI: 10.1016/S1095-6433(02)00179-4

Abstract: Tarpon have high resting or routine hematocrits (Hct) (37.6+/-3.4%) and hemoglobin concentrations (120.6+/-7.3 gl(-1)) that increased significantly following bouts of angling-induced exercise (51.9+/-3.7% and 142.8+/-13.5 gl(-1), respectively). Strenuous exercise was accompanied by an approximately tenfold increase in blood lactate and a muscle metabolite profile indicative of a high energy demand teleost. Routine blood values were quickly restored only when this facultative air-breathing fish was given access to atmospheric air. In vitro studies of oxygen transport capacity, a function of carrying capacity and viscosity, revealed that the optimal Hct range corresponded to that observed in fish under routine behaviour. During strenuous exercise however, further increase in viscosity was largely offset by a pronounced reduction in the shear-dependence of blood which conformed closely to an ideal Newtonian fluid. The mechanism for this behaviour of the erythrocytes appears to involve the activation of surface adrenergic receptors because pre-treatment with propranolol abolished the response. High levels of activity in tarpon living in hypoxic habitats are therefore supported by an elevated Hct with adrenergically mediated viscosity reduction, and air-breathing behaviour that enables rapid metabolic recovery.

Using dietary metabarcoding analyses to characterise waterbirds–agriculture interactions

Publisher: Wiley

Date: 26-09-2022

DOI: 10.1111/1365-2664.14272

Abstract: Globally, the use of agricultural fields by waterbirds has increased, resulting in conflicts with farmers. Designing effective management strategies to resolve these conflicts requires understanding the species' resource use. Dietary analyses can shed light on the extent of consumption of agricultural crops and surrounding natural resources, as well as the potential relationship between diet and an in idual's body condition and ultimately its fitness. We examined the dietary composition of the tropical magpie goose Anseranas semipalmata , seasonally utilising a mixed natural‐agricultural landscape of northern Australia. We used DNA metabarcoding of intestinal contents from hunted geese to reconstruct in idual diets and evaluated body condition from morphometric measurements. We compared the relative contribution of agricultural and natural foods to dietary composition, and investigated how this contribution varied spatially, temporally and among in iduals that differed in body condition. We found that geese consumed both agricultural and naturally occurring plants assigned to at least 35 taxa. The most frequent and abundant taxa belonged to three families: Poaceae (grasses), Cyperaceae (sedges) and Anacardiaceae (mangoes). Dietary composition varied substantially among s ling sites and over time but not with body condition of geese. Synthesis and applications . We used a novel approach to investigate the diet of a waterbird perceived as problematic across an agricultural landscape in tropical Australia. We showed that in iduals forage opportunistically, and that agricultural crops, while eaten, may not represent an essential part of geese diet across the study region. The knowledge acquired provides new insights into the species' foraging ecology offering clear alternatives for mitigating goose–agriculture interactions. Providing disturbance‐free alternative foraging areas or minimising the attractiveness of targeted agricultural fields (e.g. shorter grass, alternative ground cover) may alleviate crop consumption while benefiting the species' long‐term conservation. While also highlighting the limitations of DNA metabarcoding, our dietary study emphasises the potential of this methodology to improve our understanding of crop damage by wildlife, allowing effective evaluation of management requirements.

Demonstration of Pollinator-Mediated Reproductive Isolation in Sexually Deceptive Species of Chiloglottis (Orchidaceae: Caladeniinae)

Publisher: CSIRO Publishing

Date: 1996

DOI: 10.1071/BT9960015

Abstract: Three designs of field choice experiments were used to demonstrate complete reproductive isolation by sexually deceived thynnine pollinators (Neozeleboria Rohwer spp.) in eight species of Chiloglottis R.Br. Four species, Chiloglottis diphylla R.Br., C. formicifera Fitzg., C. pluricallata D.L.Jones and C. valida D.L.Jones, attracted only one wasp species, but the other four, C. platyptera D.L.Jones, C. seminuda D.L.Jones, C. trilabra Fitzg. and C. reflexa Labill. Druce exhibited multiple species attraction. Wasps visiting orchids were classified as major responders if they exhibited behaviour which could potentially result in pollination, by contrast to minor responders which did not. Major responders occurring sympatrically with the orchid were termed confirmed, potential or putative pollinators on the basis of observation of pollinia removal or deposition, pseudocopulation with the labellum, or arrival at bait flowers with pollinia from local orchid populations, respectively. Each Chiloglottis species had a single Neozeleboria species as confirmed or potential pollinator. The data confirmed that field pollinator choice tests can be used to distinguish cryptic sexually deceptive orchid species, and that specific pollinators may be used reliably as taxonomic characters in Chiloglottis.

Energetic costs of digestion in Australian crocodiles

Publisher: CSIRO Publishing

Date: 2011

DOI: 10.1071/ZO12018

Abstract: We measured standard metabolic rate (SMR) and the metabolic response to feeding in the Australian crocodiles, Crocodylus porosus and C. johnsoni. Both species exhibit a response that is characterised by rapidly increasing metabolism that peaks within 24 h of feeding, a postfeeding metabolic peak (peak O2) of 1.4–2.0 times SMR, and a return to baseline metabolism within 3–4 days after feeding. Postfeeding metabolism does not significantly differ between species, and crocodiles fed intact meals have higher total digestive costs (specific dynamic action SDA) than those fed homogenised meals. Across a more than 100-fold range of body size (0.190 to 25.96 kg body mass), SMR, peak O2, and SDA all scale with body mass to an exponent of 0.85. Hatchling (≤1 year old) C. porosus have unexpectedly high rates of resting metabolism, and this likely reflects the substantial energetic demands that accompany the rapid growth of young crocodilians.

Some Physiological Consequences of Estivation by Freshwater Crocodiles, Crocodylus johnstoni

Publisher: JSTOR

Date: 03-1996

DOI: 10.2307/1564699

Control threshold analysis for the tea mosquito bug, Helopeltis pernicialis (Hemiptera: Miridae) and preliminary results concerning the efficiency of control by the green ant, Oecophylla smaragdina (H

Publisher: Informa UK Limited

Date: 1997

DOI: 10.1080/096708797228735

Solar Absorptance of Some Australian Lizards and Its Relationship to Temperature

Publisher: CSIRO Publishing

Date: 1996

DOI: 10.1071/ZO9960059

Abstract: The absorptance to solar radiation, integrated across a wide range of wavelengths, was measured for selected species of Australian lizards. Some, but not all, agamids demonstrated the ability to change absorptance. None of the varanid lizards measured changed absorptance, including Varanus storri, which had been reported to change colour. An energy balance model was used to explore the effects of absorptance, changes in absorptance, and body size in varanid lizards, the dragon Ctenophorus caudicinctus (which changed absorptance from 77.0 to 87.7%) and the frillneck lizard (Chlamydosaurus kingii). Although higher absorptance values generally result in higher body temperatures, the effect of body size is great and must be taken into account in comparisons. Although some species with high absorptances are associated with relatively cool climates (Varanus rosenbergi) or with a semi-aquatic lifestyle (V. mertensi), the absorptances of other species are not as easily explained [such as the high absorptances of the tropical terrestrial V. panoptes (87%) and the tropical arboreal V. scalaris (86%)]. The absorptances of more species are required before the importance of climate and phylogenetic relationships can be fully evaluated. To facilitate future measurements, the apparatus used in this study is described in detail.

New Pond—Indicator Bacteria to Complement Routine Monitoring in a Wet/Dry Tropical Wastewater Stabilization System

Publisher: MDPI AG

Date: 19-11-2019

DOI: 10.3390/W11112422

Abstract: Bacteria monitoring is a critical part of wastewater management. At tropical wastewater stabilization ponds (WSPs) in north Australia, sanitation is assessed using the standard fecal indicator bacteria (FIB) Escherichia coli and Enterococci. However, these bacteria are poor surrogates for enteric pathogens. A focus on FIB misses the majority of pond-bacteria and how they respond to the tropical environment. Therefore, we aimed to identify the unknown pond bacteria and indicators that can complement E. coli to improve monitoring. Over two years, we measured the bacterial community in 288 wastewater s les during the wet and dry seasons. The WSP community was spatially and temporally dynamic. Standard pond-water physicochemical measures like conductivity poorly explained these community shifts. Cyanobacteria represented % of the WSP bacterial population, regardless of s le timing and location. Fecal bacteria were abundant in the first pond. However, in downstream ponds, these bacteria were less abundant, and instead, environmental taxa were common. For each pond, we identified a bacterial fingerprint that included new candidate bacterial indicators of fecal waste and processes like nitrogen removal. Combining the new indicators with standard FIB monitoring represents a locally relevant approach to wastewater monitoring that facilitates new tests for human fecal pollution within tropical climates.

Diet and habitat use of frillneck lizards in a seasonal tropical environment

Publisher: Springer Science and Business Media LLC

Date: 04-1996

DOI: 10.1007/BF00334405

Physiological ecology of frillneck lizards in a seasonal tropical environment

Publisher: Springer Science and Business Media LLC

Date: 04-1996

DOI: 10.1007/BF00334406

Physical and biotic determinants of space utilization by the Galapagos land iguana (Conolophus pallidus)

Publisher: Springer Science and Business Media LLC

Date: 04-1985

DOI: 10.1007/BF00378565

Frogs host faecal bacteria typically associated with humans

Publisher: Canadian Science Publishing

Date: 07-2017

DOI: 10.1139/CJM-2017-0119

Abstract: Tree frogs commonly access drinking water tanks this may have human health implications. Although hibians might not be expected to host mammalian faecal indicator bacteria (FIB), it is possible that they may have human FIB on their skin after exposure to human waste. We collected faeces and skin wash from green tree frogs (Litoria caerulea) from a natural environment, a suburban site, and a suburban site near a creek occasionally contaminated with sewage effluent. We used molecular techniques to test for FIB that are routinely used to indicate human faecal contamination. Enterococci colonies were isolated from both faecal and skin wash s les, and specific markers (Enterococcus faecium and Bacteroides thetaiotaomicron) were found in frog faeces, demonstrating that these markers are not human- or mammalian-specific. Bacteroides thetaiotaomicron was detected in frogs from both natural and urban sites, but E. faecium was only associated with the sewage impacted site.

Phylogeography of pollinator-specific sexually deceptive Chiloglottis taxa (Orchidaceae): Evidence for sympatric divergence?

Publisher: Wiley

Date: 09-2005

DOI: 10.1111/J.1365-294X.2005.02659.X

Habitat Differences in Body Size and Shape of the Australian Agamid Lizard,Lophognathus temporalis

Publisher: Society for the Study of Amphibians and Reptiles

Date: 09-2012

DOI: 10.1670/11-084

Fast Growth and Early Maturation in a Viviparous Sit-and-Wait Predator, the Northern Death Adder (Acanthophis praelongus), from Tropical Australia

Publisher: Society for the Study of Amphibians and Reptiles

Date: 09-2002

DOI: 10.1670/0022-1511(2002)036[0505:FGAEMI]2.0.CO;2

Inter- and intra-individual variation in body temperatures of the galapagos land iguana (Conolophus Pallidus

Publisher: Elsevier BV

Date: 02-1985

DOI: 10.1016/0306-4565(85)90010-5

Field Hydration State Varies among Tropical Frog Species with Different Habitat Use

Publisher: University of Chicago Press

Date: 03-2014

DOI: 10.1086/674537

Abstract: We have previously shown that ecological habit (e.g., arboreal, terrestrial, hibious) correlates with thermoregulatory behaviors and water balance physiology among species of hylid frogs in northern Australia. We hypothesized that these frogs would be different with respect to their field hydration states because of the challenges associated with the different ecological habits. There are very few data on the hydration levels that frogs maintain in the field, and the existing data are from disparate species and locations and do not relate hydration state to habit or changes in seasonal water availability. We measured the hydration state of 15 species of frogs from tropical northern Australia to determine the influences of ecological habit and season on the hydration state that these frogs maintain. As predicted, frogs were significantly less hydrated in the dry season than they were in the wet season and showed significantly higher variation among in iduals, suggesting that maintaining hydration is more challenging in the dry season. In the wet season, terrestrial species were significantly less hydrated than arboreal or hibious species. During the dry season, hibious species that sought refuge in cracking mud after the pond dried were significantly less hydrated than terrestrial or arboreal species. These data suggest that hydration behaviors and voluntary tolerance of dehydration vary with habitat use, even within closely related species in the same family or genus. Terrestrial and arboreal species might be expected to be the most vulnerable to changes in water availability, because they are somewhat removed from water sources, but the physiological characteristics of arboreal frogs that result in significant cutaneous resistance to water loss allow them to reduce the effects of their dehydrating microenvironment.

Effect of Season on Oral and Gastric Nematodes in the Frillneck Lizard from Australia

Publisher: Wildlife Disease Association

Date: 04-1998

DOI: 10.7589/0090-3558-34.2.381

Abstract: The prevalence and intensity of nematodes from the stomach and the prevalence of nematodes in the oral cavity were recorded in the frillneck lizard, Chlamydosaurus kingii, in Kakadu National Park (Australia) between 1991 and 1994, in order to determine whether or not a seasonal pattern was evident. Seven species were recorded Strongyluris paronai, Skrjabinopatera goldmanae, Abbreviata confusa, Abbreviata anomala, Physalopteroides filicauda, Kreisiella sp. and a species of Trichostrongyloidea. Only S. paronai showed a seasonal pattern. Only larval S. paronai occurred in stomach s les and larvae of this species occurred seasonally in the oral cavity of C. kingii, substantiating earlier findings that this genus migrates within the host. The occurrence of S. paronai in the oral cavity coincided with the highest prevalence and intensity of S. paronai in stomach s les. This shows a previously unrecorded aspect in the life cycle of this nematode species. Prevalence of S. paronai was positively correlated with ambient temperature which is highest in the months preceding the monsoonal rains, and coincides with an increase in field metabolic rate and general activity of the host.

Capillary and mitochondrial unit in muscles of a large lizard

Publisher: American Physiological Society

Date: 04-1989

DOI: 10.1152/AJPREGU.1989.256.4.R982

Abstract: We asked whether capillaries and mitochondria form a structural and functional unit in the musculature of the Cuban iguana (Cyclura nubila) similar to that found in mammals. We found a significant correlation between capillary length density [Jv(c, f)] and mitochondrial volume density [Vv(mt, f)] of the musculature with a slope that revealed that on average 3.5 km of capillaries were associated with each milliliter of mitochondria (vs. approximately 11 km/ml in mammals). These capillaries had a diameter of 9 microns (vs. 4.5 microns in mammals), and the mitochondria had a surface density of the inner membranes of 25 m2/ml (vs. 30-45 m2/ml in mammals). These dimensions resulted in ratios of capillary to mitochondrial volume (0.22 ml/ml) and capillary wall to mitochondrial membrane surface area (39 cm2/m2) that were similar in Cyclura to those found in mammals (approximately 0.18 ml/ml and 35-52 cm2/m2, respectively). Also in agreement with mammalian values were the average oxidative capacity of the mitochondria derived from maximum rate of O2 consumption (VO2max) during exercise at 37 degrees C and the inner mitochondrial membrane surface area [S(im)] of the musculature [VO2max/S(im) = 0.04 vs. 0.06-0.15 ml O2.m-2.min-1 in mammals]. These common structural and functional relationships support the notion that capillaries and mitochondria represent a similar fundamental unit in muscles of both Cyclura and mammals.

Response of reptiles to weed-control and native plant restoration in an arid, grass-invaded landscape

Publisher: Elsevier BV

Date: 12-2020

DOI: 10.1016/J.GECCO.2020.E01325

Energetics of bluetongue lizards ( Tiliqua scincoides ) in a seasonal tropical environment

Publisher: Springer Science and Business Media LLC

Date: 08-2003

DOI: 10.1007/S00442-003-1301-9

Abstract: We studied the physiological ecology of bluetongue lizards (Tiliqua scincoides) on the Adelaide River floodplain in tropical Australia to determine the seasonal patterns of energy expenditure and to determine the mechanisms by which seasonal differences were achieved. Field metabolic rates (FMR) were significantly lower in the dry season (37.6 kJ kg(-1) day(-1) n=9) than in the wet (127.3 kJ kg(-1) day(-1) n=7). Water flux was also lower in the dry season (6.8 ml kg(-1) day(-1) n=9) than in the wet (39.4 ml kg(-1) day(-1) n=7). Measurements of body temperatures (T(b)) and movements of free-ranging animals, and standard metabolic rate (SMR) of recently caught animals, allowed a detailed analysis of energy budgets for wet and dry seasons. In the dry, bluetongue lizards expended 90 kJ kg(-1) day(-1) less energy than in the wet season. Unlike some other lizards of the wet-dry tropics, SMR did not differ between seasons. About 5% of the seasonal difference in FMR was due to lower night time T(b) during the dry season, and about 7% was due to lower diurnal T(b). The remaining 88% of the decrease in energy expended in the dry season was due to a substantial decrease in other costs that may include reproduction, growth, digestion and activity. If we assume the animals fed daily and the costs of digestion are taken into account, the estimates are: 14% of the savings result from lower T(b) at night, 20% from lower T(b) in the day, and 66% result from decreased activity. It is therefore apparent that, unlike some agamid and varanid lizards that use a combination of behavioural and physiological mechanisms to conserve energy when food and water are limited, bluetongue lizards primarily use behavioural mechanisms to achieve a dramatic reduction in energy expenditure in the dry season.

Condensation onto the Skin as a Means for Water Gain by Tree Frogs in Tropical Australia

Publisher: University of Chicago Press

Date: 10-2011

DOI: 10.1086/661908

Abstract: Green tree frogs, Litoria caerulea, in the wet-dry tropics of northern Australia remain active during the dry season with apparently no available water and temperatures that approach their lower critical temperature. We hypothesized that this surprising activity might be because frogs that are cooled during nighttime activity gain water from condensation by returning to a warm, humid tree hollow. We measured the mass gained when a cool frog moved into either a natural or an artificial hollow. In both hollows, water condensed on cool L. caerulea, resulting in water gains of up to 0.93% of body mass. We estimated that the water gained was more than the water that would be lost to evaporation during activity. The use of condensation as a means for water gain may be a significant source of water uptake for species like L. caerulea that occur in areas where free water is unavailable over extended periods.

Ontogenetic comparisons of standard metabolism in three species of crocodilians

Publisher: Public Library of Science (PLoS)

Date: 09-02-2017

DOI: 10.1371/JOURNAL.PONE.0171082

Energetic costs of activity by lizards in the field

Publisher: Wiley

Date: 06-1997

DOI: 10.1046/J.1365-2435.1997.00099.X

Charles Darwin University

Location: Australia

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Discovery Projects - Grant ID: DP0559093

Start Date: 2005

End Date: 07-2008

Amount: $220,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP210102176

Start Date: 02-2021

End Date: 01-2025

Amount: $450,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0882478

Start Date: 09-2008

End Date: 06-2012

Amount: $252,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0879605

Start Date: 04-2008

End Date: 04-2011

Amount: $400,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0879851

Start Date: 2008

End Date: 12-2010

Amount: $270,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP190102395

Start Date: 03-2019

End Date: 05-2023

Amount: $422,000.00

Funder: Australian Research Council