Questionable flaws in Invasive Species Council cat impacts to wildlife

We need to halt any approaches from demonising all cats including domestic cats in urban areas, and look at ethical, humane, effective and proven cat management practices.

1. Video with summarised hot topics
2. Aligning the context of cats with bigger issues & risks for our wildlife
3. APWF predominant flaws in ISC & cohorts’ studies
4. APWF Submission NSW Inquiry Management of Cat Populations
5. Aussie research: Bella and Charlie Are Not the Problem – It’s Us: The Real Drivers of Wildlife Decline in NSW
6. Professor Jacquie Rand APWF @ the Australian Veterinarian Association Conference: Rethinking urban cat management
7. Recent Canadian research on benefits of desexing and regularly feeding a colony of cats to minimise wildlife predation
8. Aussie Study: Do Pet Cats Deserve the Disproportionate Blame for Wildlife Predation Compared to Pet Dogs?

Video with summarised hot topics

Aligning the context of cats with bigger issues & risks for our wildlife

We need to humanely respond to the cat crisis with proven effective approaches and align with initiatives to protect wildlife.

In 2024, Dr Colin Salter, Policy Lead, WIRES, at the hearings for the NSW Inquiry Management of Cat Populations included there is:

“much bigger risks to wildlife that we should be focusing on”
“…the key threats to wildlife are habitat destruction and fragmentation… Roads bisecting habitat is a clear impact. Connectivity is probably one of the largest threats in New South Wales”

“a disproportionate focus on cats”
“It’s easy go after something like cats. Technically, it’s an easier fix or it’s easier to be seen to be fixing it… Even though cats are a complex problem, climate change and habitat destruction are much larger and more significant”

“a very small number of calls coming through to WIRES in relation to harm caused by cats”
“For the Greater Sydney area, we’re talking around 3 per cent of calls are related to cats. About half of that is the Sydney metropolitan area, the largest Sydney metro area.”

https://www.parliament.nsw.gov.au/committees/inquiries/Pages/inquiry-details.aspx?pk=3011#tab-hearingsandtranscripts

“Habitat loss and clearing has caused the extinction of 62 Australian terrestrial species since European colonisation… The state of the environment in Australia is deteriorating as a result of cumulative and increasing pressures from climate change, habitat loss, invasive species, pollution and resource extraction… We can expect many ecosystems to undergo sudden, unpredictable and often irreversible transitions to new states leading to biodiversity decline, erosion, loss of soil fertility and an increase in greenhouse gas emissions.” https://www.dcceew.gov.au/sites/default/files/documents/6.%20DCCEEW-SOE_factsheet_Habitat%20and%20Natural%20Capital.pdf

We recognise the issues for cats hunting, we seek a normalised priority and appropriate local responses for best outcomes for wildlife and cats.

APWF predominant flaws in ISC & cohorts’ studies

The Australian Pet Welfare Foundation position statement on cat impacts to wildlife provide valid insights based on research and scientific evidence, predominantly Australian and focused on domestic cats.

The APWF position statement includes assessments of flaws in ISC & cohorts’ studies on significant impacts to wildlife which are predominantly based on feral cat studies with layers of assumptions for domestic cats, including:

• flawed data collection
• flawed calculations
• flawed study designs
• estimates & extrapolated estimates: do not represent evidence/ proof

https://petwelfare.org.au/position-statements/domestic-cats

APWF Submission NSW Inquiry Management of Cat Populations

Response to TOR (a) The impact of cats on threatened native animals in metropolitan and regional settings (page 15) based on evidence based research includes:

• “there is no scientific evidence that domestic cats (cats that live in the vicinity of people), have any viability or conservation impacts at a population level on native wildlife”
• “Australian population studies have not found a measurable effect of domestic cats on native wildlife”
• “feral cat impacts are often wrongly attributed to domestic cats, even though these are two distinct and geographically separate populations of cats with different behaviour and ecology”
• “the estimates of pet and stray cat predation of wildlife are based on flawed theoretical calculations that assume all pet cats predate similarly, even if contained inside”
• flawed assumptions that “stray cats being fed by people predate similarly to cats in rubbish dumps in small rural towns or in parks with bushland”
• Study 1 “…pet cats did not negatively impact the species diversity or abundance of small and medium-sized mammals at these sites and that vegetation characteristics are likely more important. In addition, cat related by-laws, including prohibition of cat ownership, had no measurable benefits on wildlife.”
• Study 2: “habitat destruction and degradation were the critical factors affecting richness of bird species, rather than cats or dogs”
• Study 3: “hunting by domestic dogs and cats appears to be of relatively minor conservation concern compared with issues such as habitat loss and urban development”
• Study 4: “Bandicoot abundance was higher at novel sites where cats were common, than at remnant sites (cats were uncommon), with the highest abundance at the novel site with the most urbanised surroundings”
• Study 5: “Stray cats in urban areas are not a significant cause of native wildlife predation but predate introduced rodents”
• Study 6: “There was no evidence that stray cats in a regional town were predating native wildlife to provide their energy needs but were predating introduced rodents.”

Highly inaccurate estimates of domestic cat impacts on Australian native wildlife populations (page 19) includes the numbers and methods are based on extrapolating findings from limited studies resulting “in highly inaccurate conclusions”

• “the effects of domestic cats are extrapolated from just 5 studies”, 3 “were from rubbish dumps in small rural towns”, 2 “explicitly stated they only analysed stool samples that contained evidence of wildlife remains and excluded those that had evidence of cat food”
• “calculated that all 0.7 million unowned cats living in highly modified environments (domestic cats) predated similarly to those samples analysed” and “results are in no way representative of urban domestic cats, the vast majority are fed intentionally by humans”
• “the effects of pet cats were extrapolated from 25 to 40-year-old studies of cats that were observed to predate and… then assumed that all 3.88 million pet cats predated similarly… estimated that every pet cat, regardless of whether it was contained inside or never seen to predate, killed 15.6 birds a year”
• resulting in “gross overestimation of pet cat predation” as “many pet cats are confined solely inside, and not all cats predate, particularly older cats”

https://petwelfare.org.au/government-submissions/new-south-wales

Aussie research: Bella and Charlie Are Not the Problem – It’s Us: The Real Drivers of Wildlife Decline in NSW

Importantly for the current prominent perceptions of cat impacts to wildlife: “all animal attacks combined accounted for 4.4% of threatened species rescues; dog-related rescues were more than three times greater than cat-related rescues, with cat-related rescues comprising 0.6% of all threatened species rescues”.

The current strong public focus on cats and impacts to wildlife “risks diverting attention away from other more major and preventable impacts on wildlife in urban areas. These include habitat loss and fragmentation, vehicle collisions, extreme weather, and hazards linked to roads, buildings, and other human structures”.

Conclusion include:

• Companion animal attacks were causing “a small proportion of rescues overall, with dog-related rescues more than three times as common as cat-related rescues”
• Gains in conservation “are likely to come from preventing harm before it occurs and increasing survival through early intervention”
• Prevention efforts should be focused “on the major human-related drivers identified in this study offers the strongest opportunity to reduce wildlife rescues and improve outcomes for threatened species and wildlife rescuers”
• Acknowledging and responding to these factors and drivers “will be essential if conservation policy is to achieve meaningful reductions in threatened wildlife injury and mortality and protect human wellbeing.”
• “Overall, threatened species most often entered care due to adverse weather events, unsuitable environment, hazardous materials, and vehicle collisions—suggesting that prevention efforts targeting these causes are likely to avert more harm than a primary focus on pet cats.”

https://www.preprints.org/manuscript/202604.1191

Professor Jacquie Rand APWF @ the Australian Veterinarian Association Conference: Rethinking urban cat management

“…councils keep relying on trapping, impounding and euthanasia to deal with free-roaming cats”

Topic: overstated wildlife impacts

Issues with the main study that is often quoted by Invasive Species Council & others:

• “all based on previously collected data by other authors”
• “Manual” data collection not verified by other scientists
• “The pet cat data is based on six publications from four studies… questionnaires from 1989… 32 to 37 years ago” (Not counted by the scientists)
• “Only two out of six were peer-reviewed. Three out of six were from the same data… they were not peer-reviewed”

Issues: Assumptions & flaws in no. of birds per year per cat, with media implying significant impacts to populations

• averaged over three studies to 4.5 birds/year, then multiplied by 3 (from another study) to estimate “the average cat catches 15.6 six birds a year”
• then multiplied by the estimate of 3.88 million cats in Australia “regardless of whether they were contained inside and regardless of their age” to estimate 61 million birds/year both native and introduced birds
• “in the abstract they say this can’t be extrapolated to a population effect, it certainly in the media it has been implied this data translates to a population effect”

The subsequent paper on Legge et al. ‘Bella and Charlie the impacts of pet cats on Australian wildlife’ used the same six publications & other studies “only one third of all the publications again were peer-reviewed and they actually calculated that the average pet cat whether it was contained inside and regardless of age caught 31 birds”

“That means everyone who owns a pet cat on average should see 10 birds a year regardless of whether the cat’s inside or not. So, you know, it really doesn’t pass the pub test” is it a “gross over estimation? Yes. Does it translate to a population effect? No.”

Recent Canadian research on benefits of desexing and regularly feeding a colony of cats to minimise wildlife predation

The research Evaluating the Effects of Managed Free-Roaming Cat Populations on Prey Through Stable Isotope Analysis: A Pilot Study from British Columbia, Canada, has a strong alignment with similar conditions in Australia of a farm location near native animals, with a sizeable cat colony dependent on humans for feeding, desexing, monitoring health etc.

“Our findings highlight the value of this [TNR and feeding] management strategy for reducing ecological impacts [hunting esp of native animals] of free-roaming cats while supporting humane population control.”

A small selection of most interesting points from the research includes:

• “Free-roaming domestic cats can affect biodiversity through their consumption of wild prey, creating challenges for both wildlife conservation and animal welfare.”
• “As TNR programs have become increasingly popular, one of the most common and persistent criticisms is that they fail to protect wildlife from predation [11,12].”
• “Before TNR, cats showed clear signs of consuming wild prey, while after TNR and food provisioning their diets shifted to resemble those of indoor cats, relying mostly on commercial food.”
• “These findings demonstrate that regular food provisioning in TNR-managed colonies, particularly when combined with broader environmental changes, can significantly alter cat diets and potentially reduce their dependence on wild prey.”
• “Our findings have important implications for both animal welfare and conservation policy. They support the position that TNR, when accompanied by systematic feeding and monitoring, can mitigate one of the most persistent criticisms of free-roaming cats: their impact on wildlife through the consumption of wild prey. By shifting dietary reliance away from prey species and toward controlled, human-provided resources, TNR programs can function as effective tools for reducing the ecological footprint of free-roaming cat populations.”

https://www.mdpi.com/2076-2615/15/21/3204

Aussie Study: Do Pet Cats Deserve the Disproportionate Blame for Wildlife Predation Compared to Pet Dogs?

“…substantial attention and blame directed at domestic cats for their hunting behavior is disproportionately large compared to that directed toward domestic dogs, given that our results show that of dogs and cats that catch prey, dogs are more likely to catch native species… hunting by domestic dogs and cats appears to be of relatively minor conservation concern compared with issues such as habitat loss and urban development”

“…median numbers of native animals caught per dog (2) or cat (3) over 6 months were low. Small skinks and lizards comprised the greatest proportion for dogs and cats, but dogs also caught larger native prey (e.g., possums, kangaroos, and wallabies). Most birds caught by dogs and cats were common or introduced (dogs: crested pigeons and lorikeets; cats: noisy miners and rosellas). To design measures that will effectively protect Australia’s native wildlife, thorough understanding of the role dogs and cats play in Australian urban ecosystems is required.”

https://www.frontiersin.org/articles/10.3389/fvets.2021.731689/full