ORCID Profile
0000-0001-8658-2811
Current Organisation
Australian Wildlife Conservancy
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/PC19053
Abstract: Globally, freshwater fishes are declining at an alarming rate. Despite much evidence of catastrophic declines, few Australian species are listed as threatened under national legislation. We aim to help redress this by identifying the Australian freshwater fishes that are in the most immediate risk of extinction. For 22 freshwater fishes (identified as highly threatened by experts), we used structured expert elicitation to estimate the probability of extinction in the next ~20 years, and to identify key threats and priority management needs. All but one of the 22 species are small (& mm total length), 12 have been formally described only in the last decade, with seven awaiting description. Over 90% of these species were assessed to have a & % probability of extinction in the next ~20 years. Collectively, the biggest factor contributing to the likelihood of extinction of the freshwater fishes considered is that they occur in small (distributions ≤44km2), geographically isolated populations, and are threatened by a mix of processes (particularly alien fishes and climate change). Nineteen of these species are unlisted on national legislation, so legislative drivers for recovery actions are largely absent. Research has provided strong direction on how to manage ~35% of known threats to the species considered, and, of these, ~36% of threats have some management underway (although virtually none are at the stage where intervention is no longer required). Increased resourcing, management intervention and social attitudinal change is urgently needed to avert the impending extinction of Australia’s most imperilled freshwater fishes.
Publisher: Springer Science and Business Media LLC
Date: 05-05-2010
DOI: 10.1007/S00114-010-0670-2
Abstract: The severity, duration and litude of extreme weather events are forecast to intensify with current climate trends, over both long (e.g. seasonal) and short (e.g. daily) time-scales. As such, the predictability of food supplies for many small endotherms is likely to become increasingly important. Numerous small mammals and birds combat food shortages using torpor, a controlled reduction in metabolic rate and body temperature that helps lower their daily energy requirements. As such, torpor often has been cited as a key feature allowing some small endotherms to survive highly unpredictable climates, such as tropics or dry deserts, but mensurative demonstrations of this are lacking. We have shown here that when a small desert marsupial, the fat-tailed dunnart (Sminthopsis crassicaudata), is offered unpredictable levels of daily food, they increase frequency of daily torpor and length of bouts compared with animals offered ad libitum food, but this was not found for animals offered a 75% [corrected] food-restricted diet. Our data suggest that simple food restriction may not be sufficient for evaluating the efficacy of torpor as a strategy for managing unpredictable climates.
Publisher: The Company of Biologists
Date: 2014
DOI: 10.1242/JEB.097006
Abstract: Animals may overcome the challenges of temperature instability through behavioural and physiological mechanisms in response to short and long term temperature changes. When ectotherms face the challenge of large diel temperature fluctuations one strategy may be to reduce the thermal sensitivity of key traits in order to maintain performance across the range of temperatures experienced. Additional stressors may limit the ability of animals to respond to these thermally challenging environments through changes to energy partitioning, or interactive effects. Ornate burrowing frog (Platyplectrum ornatum) tadpoles develop in shallow ephemeral pools that experience high diel thermal variability (& °C) and can be exposed to high levels of UV-B radiation. Here we investigated how development in fluctuating verses stable temperature conditions in the presence of high or low UV-B radiation influences thermal tolerance and thermal sensitivity of performance traits of P. ornatum tadpoles. Tadpoles developed in either stable (24°C) or fluctuating temperatures (18-32°C) under high or low UV-B conditions. Tadpoles were tested for upper critical thermal limits and thermal dependence of resting metabolic rate and maximum burst swimming performance. We hypothesised that developmental responses to thermal fluctuations would increase thermal tolerance and reduce thermal dependence of physiological traits, and that trade-offs in the allocation of metabolic resources towards repairing UV-B induced damage may limit the ability to maintain performance over the full range of temperatures experienced. We found that P. ornatum tadpoles were thermally insensitive for both burst swimming performance, across the range of temperatures tested, and resting metabolic rate at high temperatures independent of developmental conditions. Maintenance of performance led to trade-off for growth under fluctuating temperatures and UV-B exposure. Temperature treatment and UV-B exposure had an interactive effect on upper critical thermal limits possibly due to the up-regulation of the cellular stress response. Thermal independence of key traits may allow P. ornatum tadpoles to maintaining performance in the thermal variability inherent in their environment.
Publisher: Springer Science and Business Media LLC
Date: 05-10-2010
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.CBPA.2015.09.007
Abstract: Temperature and ultraviolet radiation (UVR) are key environmental drivers that are linked in their effects on cellular damage. Exposure to both high temperatures and UVR can cause cellular damage that result in the up-regulation of common protective mechanisms, such as the induction of heat shock proteins (Hsps) and antioxidants. As such, the interactive effects of these stressors at the cellular level may determine physiological limits, such as thermal tolerance. Furthermore, antioxidant activity is often thermally sensitive, which may lead to temperature dependent effects of UVR exposure. Here we examined the interactive effects of temperature and UVR on upper thermal limits, Hsp70 abundance, oxidative damage and antioxidant (catalase) activity. We exposed Limnodynastes peronii tadpoles to one of three temperature treatments (constant 18°C, constant 28°C and daily fluctuations between 18 and 28°C) in the presence or absence of UVR. Tadpoles were tested for upper thermal limits (CTmax), induction of Hsp70, oxidative damage and catalase activity. Our results show that CTmax was influenced by an interactive effect between temperature and UVR treatment. For tadpoles kept in cold temperatures, exposure to UVR led to cross-tolerance to high temperatures, increasing CTmax. Plasticity in this trait was not fully explained by changes in the lower level mechanistic traits examined. These results highlight the difficulty in predicting the mechanistic basis for the interactive effects of multiple stressors on whole animal traits. Multifactorial studies may therefore be required to understand how complex mechanistic processes shape physiological tolerances, and determine responses to environmental variation.
Publisher: CSIRO Publishing
Date: 29-04-2020
DOI: 10.1071/AM20003
Abstract: The eastern barn owl (Tyto delicatula) is a significant native predator of small mammals in Australia. Regurgitated pellets can provide important data on species presence, current or historical changes in mammal fauna over time, or data on cryptic or threatened species. We collected 125 pellets from Cravens Peak reserve, Simpson Desert, Queensland, and examined the contents, including changes in diet over time (using age of pellet as a proxy) and the relative importance of different prey. In total, 642 unique prey items were recorded, 92% of which were mammals. Small rodents were the dominant prey – Mus musculus and Pseudomys hermannsburgensis, and the presence of Notomys cf. fuscus, Pseudantechinus cf. mimulus and Dasycercus blythi were all significant, being range extensions. Such data add to more traditional or novel techniques to record community changes over time.
Publisher: BirdLife Australia, Ltd.
Date: 2023
DOI: 10.20938/AFO40130149
Abstract: Monitoring the changes in occurrence and abundance of wildlife communities over time is important for more effective and targeted management and understanding long-term changes due to local and global environmental influences. In this study, we report on the first systematic bird survey carried out on Edgbaston Reserve, a protected area on the boundary of tropical and semi-arid bioregions in north-central Queensland. We systematically s led the bird fauna at 24 sites over five surveys between 2018 and 2020, using a combination of 2-ha area searches and timed nocturnal censuses. We examined variation in composition and species abundance across the surveys using multivariate, regression and non-parametric analyses. A total of 6201 bird records comprising 123 species was collected. Forty-six species exhibited significant variation in abundance across the six s led habitat types (Ironbark, Gidgee and Escarpment woodlands, Springs, Spinifex grasslands and Mitchell Grass Downs). Species composition also varied significantly across habitats and surveys, and there were clear differences in the Spinifex and Mitchell grass bird communities compared with those in the woodlands. Twenty species were recorded in only one of the five surveys, and 17 species were recorded in significantly higher abundance in some survey years, associated with an influx of granivores and nomadic and migratory species. The location of the property on the boundary of woodlands and more arid grasslands that contain springs, and the contrasting mix of eastern- and western-distributed birds, suggests that the continued monitoring of the avifauna provides an important opportunity to investigate long-term trends, linked to environmental change and annual management, to assist the preservation of this important bird community situated on the edge of two bioregions.
No related grants have been discovered for Pippa Kern.