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Improving nine lives: Trialling and assessing management strategies for stray cats (Felis catus) in Australia

Crawford, Heather M. (2019) Improving nine lives: Trialling and assessing management strategies for stray cats (Felis catus) in Australia. PhD thesis, Murdoch University.

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Domestic cats exist along a ‘Cat Continuum’ with complete independence from people at one end (‘feral cats’) and total reliance on people for their survival at the other (‘pet cats). Cats partly dependent on human provisioning (‘stray cats’) are in the middle of the continuum, living alongside people in urban environments. The ability of cats to transition along the Cat Continuum means that management strategies for stray cats necessarily overlap with strategies for pet and feral cats. In Australia, the ecology, behaviour and management of feral and pet cats have been well researched; however, stray cats have received less scientific attention.

The Australian Cat Action Plan (ACAP, 2018) is a practical guide developed by the Animal Welfare League of Queensland to aid government and NGO stakeholders improve the management and welfare of pet and stray cats, and to reduce national euthanasia rates of healthy rehomeable animals (the ‘Getting 2 Zero’ euthanasia model). To achieve these changes, the number of free-roaming stray cats and the number of pet cats that are surrendered to animal shelters or abandoned/lost, need to decrease. The most logical approach is to increase desexing rates of pet cats and increase the number of stray and surrendered cats being adopted from shelters and retained in permanent homes. This Thesis contributes data to areas identified by the ACAP as needing greater scientific input. Five chapters present original research and review global and local cat literature relevant to assessment of current, and proposed, management strategies for Australian cat populations.

To increase knowledge about stray cats in Australia, the first Thesis Chapter evaluated the health and welfare of 188 stray cats that were trapped and removed from urban, commercial, peri-urban and rural locations of the city of Perth (in Western Australia); but euthanased because of untreatable injury or unsuitable temperament for rehoming. My colleagues and I tested for influence of cat demographics, location, season, parasite biomass, diet and history of supplemental feeding by people, on stray cat body condition. Overall, Perth strays were physically healthy and reproductive, with few external injuries or evidence of disease; however, helminth parasites were extremely common (detected in 95% of cats). Nearly 40% of strays consumed wildlife including two species of endemic marsupial. Alarmingly, 57.5% of strays were scavenging vast amounts of refuse including life-threatening items. Thus, stray cats need to be removed from anthropogenic environments for their own health and welfare, and control programmes should focus on areas where refuse is common and where valued native fauna exist.

In the second Thesis Chapter, face-to-face and online surveys of 957 Australian veterinarians, veterinary nurses and students of both disciplines were conducted to ascertain whether current and future professionals are willing to embrace Early Age Desexing (EAD, surgical removal of gonads before 4 months of age) to reduce the number of cats surrendered to shelters and entering stray populations because of ‘accidental’ breeding. A desktop survey of the information available to the public about cat desexing on 299 veterinary practice websites in the capital cities of all Australian States and Territories was also carried out. Survey responses revealed that compared with veterinarians and veterinary students, veterinary nurses and nursing students preferred more conservative desexing ages (i.e., preferred desexing older than 4 months), for both male and female cats. Veterinary nurses were more motivated in choice of desexing age by anaesthetic risk ‒ especially if they had less than 5 years of professional experience. Choice of minimum desexing age by veterinarians and students of both disciplines, was most influenced by the desire to reduce the number of stray cats in the community. However, there was a disconnect between attitude and practice, because many respondents concerned about cat overpopulation did not prefer EAD of male cats (28%) or female cats (39%). Therefore, even with good intentions, the age preferences of some professionals and students leave opportunity for female cats to have at least one litter. The desktop survey revealed that 55% of 299 veterinary practice websites provided no information about desexing whatsoever, or listed desexing as a service but made no age recommendations. Websites listing desexing ages recommended the same range for male and female cats, and for cats and dogs. Overall, less than 5% recommended EAD. Only four practice websites referred to the mandatory desexing legislation enacted in their respective States. Thus, there is scope to increase the practice of EAD of pet cats amongst Australian veterinary professionals and students, and to promote EAD and relevant State legislation on private practice websites.

To determine whether charging no fee for cats affects their subsequent husbandry, retention and owners’ compliance with cat-specific State legislation – the third Thesis Chapter presents results from surveys of 69 owners who adopted a cat for free during a promotional long-weekend at a Western Australian shelter. Responses were compared with those of 72 adopters who paid the regular adoption fee for their cat during a non-promotional period. There were no significant differences between the demographics, behaviour and health profiles, and fate of adopted cats in relation to the adoption fee paid. Retention of cats was high in free- and normal-fee groups (93% vs. 96%), with both cohorts of adopters exhibiting similar cat husbandry and adhering similarly to legislative requirements for responsible cat ownership. Promotion of the free adoption-drive using mixed-media attracted new cat adopters as well as previous cat adopters, which may be key to increasing overall rehoming rates to prevent euthanasia of healthy rehomeable cats.

To reduce euthanasia of healthy stray cats in Australia, the ACAP and several NGOs promote or implement Trap-Neuter-Return programmes (TNR) in which cats are trapped, desexed and released back at their point of capture to live ‘freely’ (with regular food provided by caretakers). However, TNR is currently illegal in Australia because of concerns about predation of wildlife and transmission of pathogens and zoonoses. Chapter 5 reviewed international and national (permitted) studies of TNR programmes to determine whether TNR is a suitable management strategy for stray cats in Australia. We found little evidence for short- or long-term reduction or stabilisation of TNR colonies or prevention of euthanasia. Well-funded TNR programmes can reduce colony populations if they regularly remove friendly cats for adoption and neuter almost all strays, including immigrants. However, they do not prevent euthanasia of cats, rarely desex all cats, cannot guarantee regular prophylactic or emergency health care, and encourage cat abandonment. Before TNR trials could be considered for Australia, greater scientific surety is needed. Further research from studies overseas should investigate: the short- and long-term impacts of TNR and stray cat predation on native wildlife and introduced rodents in urban areas, long-term health and fate of free-living stray cats, potential and actual impacts of TNR colonies on human health, and contingency plans need to be developed and implemented in areas where TNR has effectively failed (e.g., how much will it cost to address/mitigate negative effects of maintaining cats at concentrated densities such as zoonoses outbreaks?).

Stray and pet cats roam freely across urban locations and are a source of nuisance for many property owners. This can cause tension between private property owners, cat owners, stray cat caretakers and municipal councils. With the aim of empowering property owners with a humane method for preventing cat incursions, Chapter 6 tested the efficacy of two commercially available ultrasonic cat deterrents. After confirming in arena trials that cats are startled by these devices, field trials were carried out on the properties of 18 property owners who reported regular incursions by nuisance cats. Ultrasonic-deterrents and motion-activated cameras were setup overlooking foci of cat activity for three consecutive two-week periods. Deterrents were activated during the second monitoring period and cat activity was compared with data from the first and third periods. Seventy-eight individual cats were detected at 17 of 18 garden sites (range 2 ‒ 9 cats/garden). Over half the cats could be sexed and 65% were males. More than half were confirmed to be pets living nearby. Cats that were most active in period 1 were classified as ‘residents’; all others were ‘peripherals’. Overall, both deterrent models had similar effects, significantly reducing the frequency and duration of incursions into gardens by resident but not peripheral cats. Males were slightly more active than females over the experiment, but sexes did not vary in response to deterrents. Owned cats were more active than unowned cats, probably reflecting proximity of their residences to trial gardens. By allowing pets to roam, cat owners are complicit in cat nuisance activity and neighbourhood conflict. Many cat owners in this study also did not comply with State legislative mandates for desexing and wearing of collars with ID tags. With regular repositioning, ultrasonic deterrents offer property owners a cost-effective, humane option to reduce incursions by unwanted cats.

This Thesis contributes knowledge to several strategies identified by the ACAP (2018) as requiring greater scientific input to reduce euthanasia and improve management of stray and pet cats. Data in Thesis Chapters demonstrate that even when free-roaming stray cats are provisioned with food by people, they face significant health and welfare risks in anthropogenic environments. Strays should be therefore be actively removed from the environment, especially from areas with refuse or valued endemic fauna. To reduce unwanted breeding there is need and scope to increase practice and promotion of EAD services amongst Australian veterinary professionals. Professionals and students also need EAD training and education about their legal responsibilities under relevant State legislation. To prevent euthanasia of healthy rehomeable cats during times of overcrowding, a temporary free adoption-drive successfully alleviated strain on an animal shelter’s resources without compromising the post-adoption husbandry received by cats. Importantly, promotion of the adoption-drive attracted new adopters which is crucial for increased rehoming. Despite its emotional appeal, TNR has a questionable success rate internationally and is not a scientifically robust option for managing stray cats in Australia given existing concerns about cat welfare and wildlife protection. Private property owners seeking to reduce incursions by unwanted cats without engaging in neighbourhood conflict may find ultrasonic-deterrents useful. This Thesis also identified several stakeholders that are currently neglected in cat management strategies (e.g., ecologists and independent researchers). Issues of data and financial deficits were identified as substantial barriers to improving current, or implementing novel, stray cat management strategies. Australian State legislation for responsible cat ownership is incentive to improve management of free-roaming strays and unwanted litters, however, enforcement and public education are sorely needed. It is recommended that stakeholders adopt a holistic approach to cat management and assign adequate funding to the development and implementation of collaborative scientific strategies that reduce overpopulation.

Item Type: Thesis (PhD)
Murdoch Affiliation(s): Environmental and Conservation Sciences
Supervisor(s): Calver, Michael
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