ORCID Profile
0000-0002-5223-6619
Current Organisation
Murdoch University
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Publisher: Springer Science and Business Media LLC
Date: 17-01-2022
Publisher: Elsevier BV
Date: 07-2018
Publisher: MDPI AG
Date: 04-12-2017
DOI: 10.3390/ANI7120092
Abstract: Many healthy adult cats are euthanised annually in shelters, and novel approaches are required to reduce euthanasia rates. Waiving adoption fees is one such approach. However, concerns that less responsible owners will be attracted to free events persist among welfare groups. We evaluated evidence for differences in cat fate, health, and adherence to husbandry legislation via a case-study of a free adoption-drive for cats ≥1 year at a Western Australian shelter. Post-adoption outcomes were compared between free adopters and a control group of normal-fee adopters. The free adoption-drive rehomed 137 cats, increasing average weekly adoptions by 533%. First-time adopters were a significantly larger portion of the free cohort, as a result of mixed-media promotions. Both adopter groups selected cats of similar age sex and pelage. Post-adoption, both groups retained % cats, reporting near identical incidences of medical and behavioural problems. Adopters did not differ in legislative compliance regarding fitting collars, registering cats, or allowing cats to roam. The shelter reported satisfaction with the adoption-drive, because in addition to relieving crowding of healthy adults, adoption of full-fee kittens increased 381%. Overall, we found no evidence for adverse outcomes associated with free adoptions. Shelters should not be dissuaded from occasional free adoption-drives during overflow periods.
Publisher: Wiley
Date: 27-05-2021
DOI: 10.1111/MAM.12251
Abstract: The red fox Vulpes vulpes is one of the world’s most widespread carnivores. A key to its success has been its broad, opportunistic diet. The fox was introduced to Australia about 150 years ago, and within 30 years of its introduction was already recognised as a threat to livestock and native wildlife. We reviewed 85 fox diet studies (totalling 31693 s les) from throughout the species’ geographic range within Australia. Mammals were a major component of fox diet, being present in 70 ± 19% of s les across n = 160 locations. Invertebrates (38 ± 26% n = 130) and plant material (26 ± 25% n = 123) were also both staple foods and often the dominant food category recorded. Birds (13 ± 11% n = 137) and reptiles (10 ± 15% n = 132) were also commonly reported, while frogs were scarcely represented (1.6 ± 3.6% n = 111) in fox diet studies. Biogeographical differences reveal factors that likely determine prey availability. Diet composition varied with ecosystem, level of vegetation clearing and condition, and climate zone. S le type (i.e. stomach versus scat s les) also significantly influenced reporting of diet composition. Livestock and frogs were underrepresented in records based on analysis of scats, whereas small mammals (native rodents, dasyurid marsupials, and bats) were more likely to be recorded in studies of scats than in studies of stomach contents. Diet varied seasonally, reflecting activity patterns of prey species and food availability. This synthesis also captures temporal shifts in fox diet over 70 years (1951–2020), as foxes have switched to consuming more native species in the wake of successful broadscale biological control of the invasive European rabbit Oryctolagus cuniculus . Diet analyses, such as those summarised in this review, capture the evidence required to motivate for greater control of foxes in Australia. This synthesis also highlights the importance of integrated pest species management to meet bio ersity conservation outcomes.
Publisher: MDPI AG
Date: 16-04-2019
DOI: 10.3390/ANI9040171
Abstract: Trap-Neuter-Return (TNR) programs, in which stray cats are captured, neutered and returned to the environment are advocated as a humane, ethical alternative to euthanasia. We review the TNR literature in light of current debate over whether or not there should be further TNR trials in Australia. We revisit the problems arising from stray cats living in association with human habitation and estimate how many stray cats would have to be processed through a scientifically-guided TNR program to avoid high euthanasia rates. We also identify 10 ethical and welfare challenges that have to be addressed: we consider the quality of life for stray cats, where they would live, whether the TNR process itself is stressful, whether TNR cats are vulnerable to injury, parasites and disease, can be medically treated, stray cats’ body condition and diet, and their impacts on people, pet cats, and urban wildlife, especially endemic fauna. We conclude that TNR is unsuitable for Australia in almost all situations because it is unlikely to resolve problems caused by stray cats or meet ethical and welfare challenges. Targeted adoption, early-age desexing, community education initiatives and responsible pet ownership have greater promise to minimize euthanasia, reduce numbers rapidly, and address the identified issues.
Publisher: Wiley
Date: 15-03-2022
DOI: 10.1111/DDI.13497
Abstract: Introduced predators negatively impact bio ersity globally, with insular fauna often most severely affected. Here, we assess spatial variation in the number of terrestrial vertebrates (excluding hibians) killed by two mammalian mesopredators introduced to Australia, the red fox ( Vulpes vulpes ) and feral cat ( Felis catus ). We aim to identify prey groups that suffer especially high rates of predation, and regions where losses to foxes and/or cats are most substantial. Australia. We draw information on the spatial variation in tallies of reptiles, birds and mammals killed by cats in Australia from published studies. We derive tallies for fox predation by (i) modelling continental‐scale spatial variation in fox density, (ii) modelling spatial variation in the frequency of occurrence of prey groups in fox diet, (iii) analysing the number of prey in iduals within dietary s les and (iv) discounting animals taken as carrion. We derive point estimates of the numbers of in iduals killed annually by foxes and by cats and map spatial variation in these tallies. Foxes kill more reptiles, birds and mammals (peaking at 1071 km −2 year −1 ) than cats (55 km −2 year −1 ) across most of the unmodified temperate and forested areas of mainland Australia, reflecting the generally higher density of foxes than cats in these environments. However, across most of the continent – mainly the arid central and tropical northern regions (and on most Australian islands) – cats kill more animals than foxes. We estimate that foxes and cats together kill 697 million reptiles annually in Australia, 510 million birds and 1435 million mammals. This continental‐scale analysis demonstrates that predation by two introduced species takes a substantial and ongoing toll on Australian reptiles, birds and mammals. Continuing population declines and potential extinctions of some of these species threatens to further compound Australia's poor contemporary conservation record.
Publisher: Royal Zoological Society of New South Wales
Date: 09-08-2021
DOI: 10.7882/AZ.2021.024
Abstract: The peer-reviewed Australian Zoologist, first published in 1914, is Australia’s longest-lived zoological journal. Its publication history shows changes in the zoological topics covered over the last 100 years, including the animals studied, characteristics of the authors and readership, and the influence of the databases used to study the journal on information retrieval. Searches in different databases retrieved different numbers of papers Scopus (including secondary documents not in the database but cited by documents that are in the database) was the most comprehensive. Although authors from 22 countries contributed papers over the history of the Australian Zoologist, over 90% of authors were Australian. Most international authors came from the USA, the UK, Canada and New Zealand. Approximately two-thirds of authors citing Australian Zoologist were Australian-based, but there were still 10 or more authors from each of thirty-four other countries citing Australian Zoologist: while regional, the journal has an international profile. Highly cited papers in Australian Zoologist had high mean Scopus percentile ranks (20th century 83.9, 21st century 73.7), indicating that in comparison to their fields globally, these papers are used well above average. Considering all papers published in Australian Zoologist, over time the proportion of papers in the categories ‘Bio ersity & Conservation’ and ‘Environmental Sciences & Ecology’ rose significantly, reflecting the increased research in these areas. Between 2013 and 2019, when relevant metrics are available in Scopus, Australian Zoologist declined in no metric measured while improving significantly in CiteScore, Highest Percentile, and % Cited, indicating increasing references to Australian Zoologist papers by other peer-reviewed publications. Between 2010 and 2019, 2.1% of Australian Zoologist papers were ranked within the top 10% in their fields globally, based on citation impact. Authors considering publishing in Australian Zoologist should note that longer papers are acceptable, colour imagery (including photographs) is encouraged, the journal is visible in major databases, it is cited internationally and there are no page charges.
Publisher: MDPI AG
Date: 20-12-2018
DOI: 10.3390/ANI9010002
Abstract: Surgical desexing of cats is typically carried out after six months of age (Mature Age Desexing, MAD) between 4–6 months (Traditional Age Desexing, TAD) or before four months (Early Age Desexing, EAD). We complemented existing surveys of veterinarians’ acceptance of EAD with online and face-to-face surveys, to ascertain the preferred desexing ages for cats and rationale of 957 Australian veterinarians, veterinary nurses, veterinary science students, and veterinary nursing students. A complementary survey of 299 veterinary practice websites across Australia documented any information provided about desexing cats. The most common reason for preferred desexing ages was reducing stray cat populations (30%) 78% of these respondents chose ages aligning with EAD. Vet nurses and nursing students were more conservative than vets or vet students, preferring to desex cats months. Perceived anaesthetic risk was a major motivation, especially for nurses ≤5 years’ experience. Across 299 urban practices in Australian capital cities, 55% of surveyed websites provided no information about desexing cats or listed desexing without explaining why it was necessary, or when to perform it. Increasingly, Australian legislatures mandate desexing of cats by three months of age, so the practices of some current/future veterinary professionals do not match changing legislation.
Publisher: MDPI AG
Date: 17-04-2020
DOI: 10.3390/ANI10040707
Abstract: As carnivorans rely heavily on their head and jaws for prey capture and handling, skull morphology and bite force can therefore reflect their ability to take larger or more difficult-to-handle prey. For 568 feral and stray cats (Felis catus), we recorded their demographics (sex and age), source location (feral or stray) and morphological measures (body mass, body condition) we estimated potential bite force from skull measurements for n = 268 of these cats, and quantified diet composition from stomach contents for n = 358. We compared skull measurements to estimate their bite force and determine how it varied with sex, age, body mass, body condition. Body mass had the strongest influence of bite force. In our s le, males were 36.2% heavier and had 20.0% greater estimated bite force (206.2 ± 44.7 Newtons, n = 168) than females (171.9 ± 29.3 Newtons, n = 120). However, cat age was the strongest predictor of the size of prey that they had taken, with older cats taking larger prey. The predictive power of this relationship was poor though (r2 0.038, p 0.003), because even small cats ate large prey and some of the largest cats ate small prey, such as invertebrates. Cats are opportunistic, generalist carnivores taking a broad range of prey. Their ability to handle larger prey increases as the cats grow, increasing their jaw strength, and improving their hunting skills, but even the smallest cats in our s le had tackled and consumed large and potentially ‘dangerous’ prey that would likely have put up a defence.
Publisher: Wiley
Date: 06-03-2021
DOI: 10.1111/JZO.12869
Abstract: Accurate determination of chronological age for cats ( Felis catus ) permits assessment of age at reproduction and growth measures, whilst understanding survivorship enables modelling of population dynamics underpinning many management questions. At present, the relative accuracy of different measures has not been compared, especially in relation to ageing live cats, where options are more limited. We tested relationships between nine ageing methods using a large database of 384 unowned, free‐roaming cats culled as part of wildlife conservation and unowned cat management. Cat heads were cleaned and scored for tooth eruption, development of the canines (root closure, length and width proportion of pulp determined by radiography), canine tooth cementum lines, tooth wear (canine tip sharpness and breakage, or absence of the P 2 ), diastema distance and closure of two cranial sutures. Tooth eruption is informative for cats up to about 8 months of age and closure of the canine root up to 12 months. In adults with closed‐rooted canine teeth, only the cementum lines and cranial sutures varied these two sets of measures were strongly correlated. We conclude by developing a predictive table for ageing cat specimens using tooth and skull features. Animals can be aged reliably over the lifespan of the animal from cadaver material, potentially adding valuable information to ecological studies where cats are culled. However, there is no way to reliably age live cats over approximately 8 months of age in the field, after which time full adult dentition is established. Similarly, radiography (to determine pulp volume) has limited use as an ageing tool for cats older than 1–2 years of age. This reduces the number of potential applications for live cats, including, for ex le, ageing unowned cats in trap–neuter–release programmes.
Publisher: CSIRO Publishing
Date: 14-07-2021
DOI: 10.1071/WR20194
Abstract: Context Invasive species are a major cause of bio ersity loss across much of the world, and a key threat to Australia’s erse reptile fauna. There has been no previous comprehensive analysis of the potential impact of the introduced European red fox, Vulpes vulpes, on Australian reptiles. Aims We seek to provide an inventory of all Australian reptile species known to be consumed by the fox, and identify characteristics of squamate species associated with such predation. We also compare these tallies and characteristics with reptile species known to be consumed by the domestic cat, Felis catus, to examine whether predation by these two introduced species is compounded (i.e. affecting much the same set of species) or complementary (affecting different groups of species). Methods We collated records of Australian reptiles consumed by foxes in Australia, with most records deriving from fox dietary studies (tallying 000 s les). We modelled presence or absence of fox predation records against a set of biological and other traits, and population trends, for squamate species. Key results In total, 108 reptile species (~11% of Australia’s terrestrial reptile fauna) have been recorded as consumed by foxes, fewer than that reported for cats (263 species). Eighty-six species have been reported to be eaten by both predators. More Australian turtle species have been reported as consumed by foxes than by cats, including many that suffer high levels of predation on egg clutches. Twenty threatened reptile species have been reported as consumed by foxes, and 15 by cats. Squamate species consumed by foxes are more likely to be undergoing population decline than those not known to be consumed by foxes. The likelihood of predation by foxes increased with squamate species’ adult body mass, in contrast to the relationship for predation by cats, which peaked at ~217 g. Foxes, but not cats, were also less likely to consume venomous snakes. Conclusions The two introduced, and now widespread, predators have both compounding and complementary impacts on the Australian reptile fauna. Implications Enhanced and integrated management of the two introduced predators is likely to provide substantial conservation benefits to much of the Australian reptile fauna.
Publisher: Elsevier BV
Date: 09-2021
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/WR16066
Abstract: Context Predation is one of the key contributors to mortality in freshwater turtles. Confirming the identity of predators is an important step towards conservation management action. Throughout Australia, the red fox (Vulpes vulpes) is suspected to apply significant and unsustainable predation pressure to turtle populations, killing adults and depredating nests however methods for confirming this are limited. Aims The present study used a range of methods to confirm predation of oblong turtle (Chelodina colliei) nests and adults by the introduced red fox. Methods First, depredated adult carapaces, and turtle egg-shell fragments from excavated nests were swabbed and analysed for trace DNA. Second, we used artificial turtle nests, monitored by camera traps, to analyse seasonal changes in the behaviour of foxes around sites where turtle nests are present, including over the nesting season. Last, we used scat analysis to identify the prevalence of turtle remains in fox diet. Key results Predominantly fox DNA was recovered from both adult carapaces and depredated eggs. In addition, camera traps recorded only foxes depredating artificial nests. Despite this evidence that foxes kill adults and excavated nests, we found that turtle remains were only a small part of the diet of foxes at this study site (hatchling or turtle egg shell were present in only 4% of 230 scats s led). The diet of these foxes was largely anthropogenic-sourced foods, such as fruit (e.g. figs, grapes, melons 81% of scats), sheep carrion (41%) and rodents (36%). Conclusions We conclude that DNA analysis, camera trapping and scat analysis are effective methods of identifying foxes as predators of adult turtle, and their nests. Furthermore, we found that anthropogenic foods (orchard crops, livestock or synanthropic species) may subsidise greater fox population size than might occur in their absence, thereby increasing potential pressure on these freshwater turtles. Implications Our findings give credence to the argument that foxes are effective predators of turtle adults and nests. In addition, the high proportion of anthropogenic food sources in the diet of foxes, and potential subsidisation, is an important consideration for land managers.
Publisher: MDPI AG
Date: 23-02-2020
DOI: 10.3390/ANI10020362
Abstract: To continue dialogue over proposed Australian trials of Trap-Neuter-Return (TNR), we applied a framework requiring identification of areas of agreement, areas of disagreement, and identification of empirical data collection required to resolve disagreements. There is agreement that Australia has a problem with stray cats, causing problems of impacts on wildlife, nuisance, disease transmission (including public health issues and exchange of diseases between stray cat and pet cat populations), poor welfare outcomes for stray cats, and an emotional burden on staff euthanising healthy stray cats. There is disagreement on whether (i) current measures are failing, leading to unacceptably high euthanasia levels, (ii) some contributors to the debate misunderstand TNR, (iii) TNR trials will reduce urban cat populations and associated problems, (iv) TNR is an ethical solution to cat overpopulation, and (v) some contributors to the debate promulgated misinformation. Although not everyone agrees that TNR trials should proceed, as a hypothetical exploration, we propose an experimental approach explicitly comparing TNR to alternatives. Trials could only be considered if other detailed and well-funded attempts at stray cat control focusing across an entire Local Government Area (LGA) prove ineffective.
No related grants have been discovered for Heather M. Crawford.