‘Science denialism’ is also about outdoor cats

Loss, S. R., Will, T., Longcore, T., & Marra, P. P. (2018). Responding to misinformation and criticisms regarding United States cat predation estimates. Biological Invasions, 20(12), 3385-3396.
Misinformation (or denialism), the disingenuous assertion of information contradicting overwhelming scientific consensus, increasingly poses a challenge for invasion biology. The issue of free-ranging domestic cats (Felis catus) provides an example of this misinformation: overwhelming consensus shows that cats are invasive species that impact wildlife and human health yet free-ranging cat advocates propagate misinformation about such impacts to support policies keeping cats on the landscape. These advocates also attempt to discredit peer-reviewed scientific research on cat impacts, as exemplified by the response to a high-profile paper estimating cats annually kill billions of U.S. birds and mammals (Loss et al. in Nat Commun 4:1396, 2013). Although favorably received by scientific and invasive species management communities, an effort was launched to discredit this paper by criticizing its methods, including a report commissioned by a feral cat advocacy group and a post by a feral cat blogger. These same organizations and individuals have made similar criticisms at scientific conferences and policy roundtables. Given the realized effects of this campaign in influencing invasive species policy, we here respond to these criticisms and show they are characterized by numerous errors and misrepresentations. We conclude that the criticisms are part of the broader campaign to fabricate doubt about outdoor cat impacts and stymie policies favoring removal of cats from the landscape. Because misinformation surrounding cats is emblematic of the broader issue of misinformation and denialism, this response will not only facilitate evidence-based policy for managing cats but also stimulate research and discussion into causes and impacts of misinformation in invasion biology.

The palaeogenetics of cat dispersal in the ancient world

Ottoni, C. et al. (2017) The palaeogenetics of cat dispersal in the ancient world. Nat. Ecol. Evol. 1, 0139.

The cat has long been important to human societies as a pest-control agent, object of symbolic value and companion animal, but little is known about its domestication process and early anthropogenic dispersal. Here we show, using ancient DNA analysis of geographically and temporally widespread archaeological cat remains, that both the Near Eastern and Egyptian populations of Felis silvestris lybica contributed to the gene pool of the domestic cat at different historical times. While the cat’s worldwide conquest began during the Neolithic period in the Near East, its dispersal gained momentum during the Classical period, when the Egyptian cat successfully spread throughout the Old World. The expansion patterns and ranges suggest dispersal along human maritime and terrestrial routes of trade and connectivity. A coat-colour variant was found at high frequency only after the Middle Ages, suggesting that directed breeding of cats occurred later than with most other domesticated animals.

Prospects for domestic and feral cat management on an inhabited tropical island

Dias, R. A., Abrahão, C. R., Micheletti, T., Mangini, P. R., de Oliveira Gasparotto, V. P., de Jesus Pena, H. F., ... & Silva, J. C. R. 2017. Prospects for domestic and feral cat management on an inhabited tropical island. Biological Invasions, 1-15.

Cat management campaigns have been implemented on several islands worldwide. However, few successful campaigns have occurred on permanently inhabited islands. Cats are known for causing severe impacts on the native insular fauna, posing an important threat to biodiversity. Moreover, this species is also responsible for zoonosis maintenance and transmission. A thorough understanding of cat population structure (e.g., supervised vs. unsupervised) is strongly suggested as a management action on inhabited islands, as it might promote more efficient and effective management of this species. Fernando de Noronha is an archipelago in the tropical Atlantic Ocean. The total cat population on the main island was estimated at 1287 animals, most of them supervised and subsidized around inhabited areas. Free-roaming cats currently threaten the endemic terrestrial fauna of Fernando de Noronha, and the cat density found by the present work is among the highest ever recorded on an island. Using population dynamic simulations, the long-term effects of reproduction control and removal of cats from the archipelago were assessed. Removal of cats was also suggested as a necessary management strategy to achieve negative population growth. In addition, it was more cost-effective than reproduction control. However, applying both removal and sterilization strategies to this population resulted in a higher population decrease than removal alone. For these reasons, a combination of reproductive control and cat eradication should be implemented in Fernando de Noronha.

Other environmental factors affects more Island foxes diet than competition with feral cats

Cypher, B.L. , Kelly E.C., Ferrara, F.J., Drost C.A., Westall, T.L. & Hudgens, B.R. 2017. Diet patterns of island foxes on San Nicolas Island relative to feral cat removal. Pacific Conservation Biology 23(2) 180-188

Island foxes (Urocyon littoralis) are a species of conservation concern that occur on six of the Channel Islands off the coast of southern California. We analysed island fox diet on San Nicolas Island during 2006–12 to assess the influence of the removal of feral cats (Felis catus) on the food use by foxes. Our objective was to determine whether fox diet patterns shifted in response to the cat removal conducted during 2009–10, thus indicating that cats were competing with foxes for food items. We also examined the influence of annual precipitation patterns and fox abundance on fox diet. On the basis of an analysis of 1975 fox scats, use of vertebrate prey – deer mice (Peromyscus maniculatus), birds, and lizards – increased significantly during and after the complete removal of cats (n = 66) from the island. Deer mouse abundance increased markedly during and after cat removal and use of mice by foxes was significantly related to mouse abundance. The increase in mice and shift in item use by the foxes was consistent with a reduction in exploitative competition associated with the cat removal. However, fox abundance declined markedly coincident with the removal of cats and deer mouse abundance was negatively related to fox numbers. Also, annual precipitation increased markedly during and after cat removal and deer mouse abundance closely tracked precipitation. Thus, our results indicate that other confounding factors, particularly precipitation, may have had a greater influence on fox diet patterns.

Bait delivery for cats using drons

Johnston, M., McCaldin, G., & Rieker, A. (2016). Assessing the availability of aerially delivered baits to feral cats through rainforest canopy using unmanned aircraft. Journal of Unmanned Vehicle Systems, 4(4), 276-281.

At least eight threatened wildlife species are at direct risk from predation by cats (Felis catus) on Christmas Island (Director of National Parks. 2014. Christmas Island biodiversity conservation plan. Canberra. Australia: Department of the Environment.). A range of strategies are now being used to manage cats across the island, including responsible ownership methods for domestic cats and lethal control tools to remove feral cats outside the township area. Unmanned aerial vehicles (UAVs) were used to drop non-toxic baits through the rainforest canopy to assess whether aerial baiting could be undertaken successfully on the island. Ground crews located 88% of baits, indicating that sufficient baits would be accessible to feral cats if broad-scale aerial baiting was to be undertaken in the future.

Dogs, catas and the fear of pest rodents

Themb’alilahlwa, A. M., Monadjem, A., McCleery, R., & Belmain, S. R. (2017). Domestic cats and dogs create a landscape of fear for pest rodents around rural homesteads. PloS one, 12(2), e0171593.

Using domestic predators such as cats to control rodent pest problems around farms and homesteads is common across the world. However, practical scientific evidence on the impact of such biological control in agricultural settings is often lacking. We tested whether the presence of domestic cats and/or dogs in rural homesteads would affect the foraging behaviour of pest rodents. We estimated giving up densities (GUDs) from established feeding patches and estimated relative rodent activity using tracking tiles at 40 homesteads across four agricultural communities. We found that the presence of cats and dogs at the same homestead significantly reduced activity and increased GUDs (i.e. increased perception of foraging cost) of pest rodent species. However, if only cats or dogs alone were present at the homestead there was no observed difference in rodent foraging activity in comparison to homesteads with no cats or dogs. Our results suggest that pest rodent activity can be discouraged through the presence of domestic predators. When different types of predator are present together they likely create a heightened landscape of fear for foraging rodents.

Cats and Tropci birds

Boeken, M. (2016). Breeding success of Red-billed Tropicbirds Phaethon aethereus on the Caribbean island of Saba. Ardea, 104(3), 263-271.

In 2011 and 2012 the breeding success of Red-billed Tropicbirds Phaethon aethereus mesonauta was monitored on Saba, a 13-km2 island in the Caribbean Netherlands. The two colonies on the south and south-west side of the island both contain approximately 100–300 nests; breeding success was zero at these sites, due to predation of newly hatched chicks by Feral House Cats. In the single large colony of Old Booby Hill (estimated to contain approximately 1000 nests) on the east side of the island, rates of predation were lower, resulting in a breeding success (survival from laying until fledging, as far as observed) of 65%. Calculations of daily survival of eggs and chicks following Mayfield, resulted in a nesting success of 48% per pair. I conservatively estimated the size of the Saba breeding population to be at least 1300–1500 pairs, which is larger than the previous estimate of 750–1000 pairs. Potentially, the number of breeding pairs may be as high as 1850 pairs.

Exposure to predators reduce immune response in birds

Navarro, C., De Lope, F., Marzal, A., & Møller, A. P. (2004). Predation risk, host immune response, and parasitism. Behavioral Ecology, 15(4), 629-635.

Predation risk may affect the allocation priorities of limiting resources by potential prey. Investment in immune function should receive reduced priority, when hosts are exposed to predators because of the costs of immune function. We tested this hypothesis by randomly exposing adult house sparrows, Passer domesticus, to either a cat, Felis catus, or a rabbit, Oryctolagus cuniculus, for 6 h while assessing their ability to raise a T-cell–mediated immune response to a challenge with phytohemagglutinin. Sparrows exposed to a cat had a significant reduction of, on average, 18% and 36% in T-cell response in two different experiments compared with sparrows that were exposed to a rabbit. In a field experiment with a barn owl, Tyto alba, or a rock dove, Columba livia, placed next to a nest-box during laying, we found a mean reduction in T-cell–mediated immune response of 20%. In males, the reduction in cell-mediated immune response owing to cat exposure increased with increasing size of the badge, which is a secondary sexual character, but only during the breeding season. In a third experiment, house sparrows were either exposed to a barn own, T. alba, or a rock dove, C. livia, and development of malarial infections was recorded during the following 6 weeks. Individual sparrows exposed to a predator had a higher prevalence and intensity of Haemoproteus malarial infection than did control individuals. Therefore, exposure to predators reduced their ability of hosts to cope with parasitism mediated through effects on immune function.

Ecology of feral cats on a Tasmanian Island

Hayde, K. A. (1992). Ecology of the feral cat Felis catus on Great Dog Island (Doctoral dissertation, University of Tasmania).

Aspects of the ecology of feral cats on Great Dog Island, Bass Strait, were investigated from May to September 1991. Population structure and dynamics, morphology and phenotypes, condition and gastro-intestinal parasites and diet were studied. A culled sample of 189 feral cats displayed a male: female ratio of 1:1 and indicated a pre-eradication density of at least 56.9 cats/km2• Juveniles and sub-adults made up 44.9% of the population. A breeding season was inferred by kitten age and by changes through time in the population structure. Approximate life expectancy was estimated to be 73-84 months for males and 85-96 months for females. Counting cementum annuli in the teeth was shown to be an effective method of age determination. The length and weight of male and female feral cats of Great Dog Island was comparable to that of feral cats found on the mainland Australian. However, a decline in the weight of females between autumn and winter suggested the occurrence of a seasonal nutritional stress. The relationship between age and length in adult males suggests that greater length offers an advantage to longevity. The presence of seven mutant pelagerelated genes, in addition to the wild type, indicated a comparatively high degree of genetic diversity within the feral cat population of Great Dog Island. The long hair allele is probably being selected against as juveniles suffer high mortality. The expression of the inhibitor allele is bias toward males. No significant relationships were found to occur between coat colour and weight or length. The analysis of gut contents showed that a total of 26 species were ingested: 2 bird, 1 mammal, 5 reptile and 18 arthropod species. The gut of 16 cats were either empty or contained only residual food stuffs. Most cats had soil and plant matter in the gut. There was no evidence of cannabalism and no human refuse was present. It is likely that some artht:opod prey were excavated. There was no advantage in age or body size in obtaining prey species. Generally, the coat skin and tooth condition of cats on Great Dog Island was very good. The nutritional condition (fat deposits) of cats suggested that cats were generally in good condition in autumn. Both males and females underwent a large decline in fat reserves from autumn to winter and reserves were further depleted as winter progressed. This resulted in the general nutiitional condition of the winter cats being poor. Gastro-intestinal parasites present were Taenia taeniaeformis, Toxocara cati and Cylicospirura felineus . Parasite infestation was biased toward females. Loss of condition did not generally result in increased susceptibility to parasite infestation. This was instead better explained as a response to diet and climate.

Impacts of introduced mammalian predators on New Zealand’s alpine fauna

O’Donnell, C. F., Weston, K. A., & Monks, J. M. (2017). Impacts of introduced mammalian predators on New Zealand’s alpine fauna. New Zealand Journal of Ecology, 41(1), 01-22.

Alpine zones are threatened globally by invasive species, hunting, and habitat loss caused by fire, anthropogenic development and climate change. These global threats are pertinent in New Zealand, with the least understood pressure being the potential impacts of introduced mammalian predators, the focus of this review. In New Zealand, alpine zones include an extensive suite of cold climate ecosystems covering c. 11% of the land mass. They support rich communities of indigenous invertebrates, lizards, fish, and birds. Many taxa are obligate alpine dwellers, though there is uncertainty about the extent to which distributions of some species are relicts of wider historical ranges. The impacts of introduced mammalian predators are well described in many New Zealand ecosystems, though little is known about the impacts of these predators on alpine fauna. Here we review the importance of alpine habitats for indigenous fauna and the impacts of introduced mammalian predators; and develop a conceptual model explaining threat interactions. Most evidence for predation is anecdotal or comes from studies of species with wider ranges and at lower altitudes. Nevertheless, at least ten introduced predator species have been confirmed as frequent predators of native alpine species, particularly among birds and invertebrates. In the case of the endangered takahe (Porphyrio hochstetteri) and rock wren (Xenicus gilviventris), stoats (Mustela erminea) are primary predators, which are likely to be impacting significantly on population viability. We also document records of mammalian predation on alpine lizards and freshwater fish. While the precise impacts on the long-term viability of threatened species have not been evaluated, anecdotal evidence suggests that predation by mammals is a serious threat, warranting predator control. Future research should focus on predicting when and where mammalian predators impact on populations of indigenous fauna, furthering our understanding of the alpine predator guild particularly through adaptive management experiments, and exploring interactions with other threats.

First population assessment of the black forest cat in Madagascar's rainforests

Farris, Z. J., Boone, H. M., Karpanty, S., Murphy, A., Ratelolahy, F., Andrianjakarivelo, V., & Kelly, M. J. (2016). Feral cats and the fitoaty: first population assessment of the black forest cat in Madagascar’s rainforests. Journal of Mammalogy, 97(2), 518-525.

Despite exceptionally high levels of biodiversity and endemism found in Madagascar, much of its wildlife remains little studied, particularly the carnivore community. The recently described, little-known black forest cat (locally known as “fitoaty”) is believed to be restricted to NE Madagascar and has been investigated only through village surveys and anecdotal accounts. From 2008 to 2012, we photographically sampled 7 forest sites with varying degrees of degradation and fragmentation across Makira Natural Park with the goals of: 1) estimating landscape occupancy for fitoaty (Felis spp.), 2) identifying variables influencing fitoaty occupancy, and 3) comparing fitoaty and feral cat (Felis spp.) occupancy across the landscape. We observed higher occupancy for fitoaty, minimal co-occurrence between fitoaty and feral cats (n = 2 sites), and strong divergence in habitat use. We provide the 1st assessment of fitoaty morphology, including comparisons with anecdotal reports, and the 1st population assessment of Madagascar’s exotic cat community with insights into factors associated with carnivore population trends in Madagascar. We suggest the described fitoaty is a phenotypically different form of the feral cat, but additional research is needed. Targeted management plans are needed to diminish the spread and potential negative effects of invasive cats across this important biologically diverse ecoregion.

Change in the probability of occupancy for Fitoaty (black) and Felis spp. (gray) in response to: a) small mammal trap success and b)  distance to village (km). Photographic sampling was conducted across the Masoala-Makira landscape from 2008 to 2012

Feral cats driving the regional extinction of a threatened rodent in northern Australia

Davies, H. F., McCarthy, M. A., Firth, R. S., Woinarski, J. C., Gillespie, G. R., Andersen, A. N., ... & Murphy, B. P. (2016). Top‐down control of species distributions: feral cats driving the regional extinction of a threatened rodent in northern Australia. Diversity and Distributions.

Aim

To investigate whether feral cats influence the distribution of Australia's largest remnant population of the threatened brush-tailed rabbit-rat Conilurus penicillatus and examine whether they influenced the extinction probability of C. penicillatus over a 15-year period (2000–2015).

Location

Melville Island, northern Australia.

Methods

In 2015, small mammal surveys were conducted at 88 sites across Melville Island, 86 of which had previously been surveyed in 2000–2002. We used single-season occupancy models to investigate correlates of the current distribution of C. penicillatus and dynamic occupancy models to investigate correlates of C. penicillatus local extinction.

Results

Our results show that C. penicillatus, which once occurred more widely across the island, is now restricted to parts of the island where feral cats are rarely detected and shrub density is high. Our results suggest that feral cats are driving C. penicillatus towards extinction on Melville Island, and hence have likely been a significant driver in the decline of this species in northern Australia more broadly. The impact of feral cats appears to be mitigated by vegetation structure.

Main conclusions

The ongoing development and implementation of methods to effectively reduce feral cat densities, coupled with the management of landscape processes to maintain shrub density, through fire management and the removal of large exotic herbivores, will contribute substantially to conserving this threatened species. This study demonstrates that the distribution of species can be strongly influenced by top-down factors such as predation, thereby highlighting the importance of including biotic interactions when investigating the distribution of predation-susceptible species.

Interactions between invasive predators, native mammals and fire in a forest ecosystem

Hradsky, B. A. K. (2016). Interactions between invasive predators, native mammals and fire in a forest ecosystem (Doctoral dissertation, University of Melbourne).

A predator’s impact upon its prey depends not only on the evolutionary history and intrinsic characteristics of the two species, but also on the structure of the environment in which they interact. Fire is a major driver of vegetation structure, and there is growing concern that fire could increase the threat that invasive predators pose to native fauna. In this thesis, I investigated the interactions between fire, two invasive predators (red foxes Vulpes vulpes and feral cats Felis catus), and a suite of native mammal species. I used four different approaches to examine this problem within a fire-prone forest ecosystem of south-eastern Australia.

At a landscape-scale, species distributions are often poorly predicted by time-since-fire. I developed a conceptual model of the potential interactions between fire and other drivers of faunal occurrence (including predation), and then used non-parametric Bayesian networks to quantify these relationships for terrestrial native mammals. I found that critical-weight-range mammals were more likely to occur at long unburnt sites with high habitat complexity, and in wetter forest types. In contrast, large macropods preferred less complex habitats and younger or drier forest. Species distributions were generally more strongly associated with habitat complexity than time-since-fire or invasive predator occurrence. Yet, because Bayesian networks captured the relationships between proximal and distal drivers, models could effectively predict the distributions of most species using only mapped and remote-sensed data.

At a finer-scale, I used a before-after control-impact experiment to investigate the short-term effects of a prescribed fire on understorey vegetation cover, native mammal occurrence, and invasive predator occurrence and diet. Associations between species occurrences and vegetation cover in unburnt forest indicated that fire was likely to promote invasive predators but disadvantage small- and medium-sized native mammals. After the fire, there was a five-fold increase in invasive predator occurrence at burnt sites, relative to the control. Concurrently, red foxes increased their consumption of medium-sized native mammals, and selected more strongly for long-nosed bandicoots Perameles nasuta and short-beaked echidnas Tachyglossus aculeatus. The occurrence of several native mammals declined after the fire, but it was difficult to distinguish the effects of the fire from seasonal variation.

I used GPS-tracking collars to investigate whether forest-dwelling red foxes selected for human-modified habitats (including recently-burnt forest). There was substantial variation in fox behaviour, highlighting the importance of considering individual variation in habitat selection studies. At a broad-scale, however, red fox habitat selection tended to vary with proximity to the forest edge. Most foxes selected for human-modified habitats such as reservoirs, roads and forest-farmland edges in their fine-scale movements, particularly at night. Two foxes whose home-ranges overlapped a burn-block intensified their use of the block immediately after fire. Yet other nearby foxes showed little response, suggesting that fire responses are highly localised.

Finally, I used an agent-based simulation model to explore how changes in vegetation cover and predator abundance after fire could affect a critical-weight-range mammal. The model confirmed that fire and predation can have synergistically negative impacts on native mammal populations in burnt forest, and that local access to unburnt refuges substantially reduces these effects.

Invasive predators are highly opportunistic, wide-ranging and thoroughly integrated into this flammable forest ecosystem. Lethal control programs for foxes need to consider fox movement across land-tenures, and could selectively target habitat features such as roadsides, forest-farmland edges and recently-burnt forest. Habitat-based management approaches might also reduce invasive predator impacts on native mammals, for example by preserving dense vegetation in unburnt refuges, or removing anthropogenic resources that subsidise predator populations within forests. Evidence-based, integrated management of threatening processes is vital to conserving native biodiversity.

Exotics replace native carnivores in Madagascar rainforest

Farris, Z. J., Kelly, M. J., Karpanty, S., Murphy, A., Ratelolahy, F., Andrianjakarivelo, V., & Holmes, C. (2016). The times they are a changin': Multi-year surveys reveal exotics replace native carnivores at a Madagascar rainforest site. Biological Conservation.

Surveys across multiple seasons or years are necessary to evaluate the effects of dynamic processes on long-term persistence of wildlife populations, such as effects of exotic species on native species populations. Unfortunately, multi-year surveys are rare, particularly for rainforest carnivore populations, and managers often rely on single-season/year, ‘snapshot’ surveys that produce static estimates of population parameters. Here we provide results using single-species, multi-year occupancy modeling from a six-year survey (2008–2013) of a rainforest carnivore community at a 15 km2 area study site within the newly established Makira Natural Park, Madagascar. We demonstrate a precipitous decline in the native carnivore community with four of the six native carnivores (falanouc Eupleres goudotii, ring-tailed vontsira Galidia elegans, broad-striped vontsira Galidictis fasciata, and brown-tailed vontsira Salanoia concolor) decreasing by at least 60% over this six-year period. In addition, we observed two exotic carnivores (small Indian civet Viverricula indica and feral cat Felis species) colonize this study site with Felis species increasing in occupancy from 0 to 0.68 by the final year. Further, we demonstrate how variables associated with human encroachment (i.e. distance to forest edge and nearest village) are most important for explaining these trends in native carnivore extirpation and exotic carnivore colonization. These findings provide additional evidence on the threat posed to native carnivore populations by the expansion of exotic carnivores worldwide. We highlight the striking increase in extirpation, and the factors influencing such changes, for native carnivores. In this manuscript, we point to the limited number of multi-year surveys to evaluate dynamic processes on long-term persistence of native wildlife populations, as well as the lack of exotic carnivore control programs in threatened ecosystems in many developing nations as factors limiting our ability to effectively conserve biodiversity across the globe.

 Line graph demonstratingthe multi-year trendsin occupancy for A) four native carnivoresand B) two exotic carnivores. Photographic surveyswere conductedfrom 2008 to 2013 at a newly established study site within the Makira Natural Park, Madagascar.

How many feral cats are in Australia?

Legge, S., Murphy, B. P., McGregor, H., Woinarski, J. C. Z., Augusteyn, J., Ballard, G., ... & Edwards, G. (2016). Enumerating a continental-scale threat: How many feral cats are in Australia?. Biological Conservation.

Feral cats (Felis catus) have devastated wildlife globally. In Australia, feral cats are implicated in most recent mammal extinctions and continue to threaten native species. Cat control is a high-profile priority for Australian policy, research and management. To develop the evidence-base to support this priority, we first review information on cat presence/absence on Australian islands and mainland cat-proof exclosures, finding that cats occur across >99.8% of Australia's land area. Next, we collate 91 site-based feral cat density estimates in Australia and examine the influence of environmental and geographic influences on density. We extrapolate from this analysis to estimate that the feral cat population in natural environments fluctuates between 1.4 million (95% confidence interval: 1.0–2.3 million) after continent-wide droughts, to 5.6 million (95% CI: 2.5–11 million) after extensive wet periods. We estimate another 0.7 million feral cats occur in Australia's highly modified environments (urban areas, rubbish dumps, intensive farms). Feral cat densities are higher on small islands than the mainland, but similar inside and outside conservation land. Mainland cats reach highest densities in arid/semi-arid areas after wet periods. Regional variation in cat densities corresponds closely with attrition rates for native mammal fauna. The overall population estimate for Australia's feral cats (in natural and highly modified environments), fluctuating between 2.1 and 6.3 million, is lower than previous estimates, and Australian feral cat densities are lower than reported for North America and Europe. Nevertheless, cats inflict severe impacts on Australian fauna, reflecting the sensitivity of Australia's native species to cats and reinforcing that policy, research and management to reduce their impacts is critical.

The population size of feral cats in natural environments in Australia fluctuates between 1.4 and 5.6 million, depending on rainfall. An additional 0.7 million feral cats live in heavily modified environments like towns and intensive farms. The maps show the model predictions for cat density in natural environments across Australia during dry-average rainfall conditions (on the left) and after extensive rainfall events (on the right). They show that cat density is fairly uniform across the continent during average-dry conditions, but extensive rainfall events cause an increase in feral cat density in the inland of Australia. As predictors, the regression model includes mean annual rainfall, mean annual temperature, tree cover, ruggedness and fox presence/absence. For islands smaller than Tasmania, island area was also included as a predictor of density (small islands have higher cat densities). The dashed lines indicate the Tropic of Capricorn.

Research, conservation and urban cat management in NZ

Kikillus, K. H., Chambers, G. K., Farnworth, M. J., & Hare, K. M. 2106. Research challenges and conservation implications for urban cat management in New Zealand. Pacific Conservation Biology.

Over the past 20 years, conservation efforts in New Zealand have moved from being concentrated in rural and isolated island locations, where exotic mammalian predators are often controlled, to begin to bring native fauna back to major cities. However, human–wildlife conflicts arise when conservation occurs in close proximity to cities. These are particularly intense when companion animals are involved either as potential predators or prey of high-value conservation animals. Within New Zealand, this conflict is particularly fraught around domestic cats (Felis catus) in the urban environment. Cats in New Zealand are recognised as major introduced predators of native fauna, but they also prey on small introduced predatory mammals. This dynamic causes much conflict between people with different attitudes towards animals; however, as yet, few studies have explored the role(s), either negative or positive, of urban cats in New Zealand. Here, we review current knowledge on domestic cats in urban New Zealand, identify gaps in knowledge and make suggestions for future research, which includes further social science research, citizen science-based research programs, market research, investigation into cat-management legislation, and more in-depth studies of cat diseases and zoonoses. These data are vital for informing the public and improving the management of urban cat populations, including mitigating conservation impacts. Urban ecologists will need to be versatile in the way they design and conduct experiments, exploiting multiple disciplines to both ensure scientific robustness, but also community and government support for uptake of results into management and legislation.

No evidence of dietary shift by native predators in sympatry with feral cats

Phillips, R. B., Winchell, C. S., & Schmidt, R. H. (2007). Dietary overlap of an alien and native carnivore on San Clemente Island, California. Journal of Mammalogy, 88(1), 173-180.


Predation by feral cats (Felis catus) is recognized as a major threat to native fauna worldwide, but the competitive effects of cats on native species have not been extensively studied. Cats occur on San Clemente Island, California, in sympatry with endemic island foxes (Urocyon littoralis clementae). We examined diets of cats and island foxes between years, seasons, and habitats to assess the potential for resource competition between the 2 species. Analysis of 602 cat and 958 fox feces revealed a high level of dietary overlap (O = 0.93) and relatively narrow niche breadths for both species (Bstandard Fox = 0.37; Bstandard Cat = 0.49). Despite the overlap in diet, cats and foxes appear to partition prey resources. Cats consume approximately equal proportions of arthropod (47.9%) and vertebrate (44.2%) prey, the latter primarily rodents (29.2%) and lizards (12.9%). In contrast, foxes appear to rely more on arthropods (57.7%), with plants (20.5%) and vertebrates (21.6%) occurring in lower, but roughly equal frequencies. Season appeared to have little effect on diet; however, diet did vary between habitats and years for both species. Diets of cats on San Clemente Island are consistent with those from other studies. We found no evidence of a dietary shift by foxes that were in sympatry with cats.

An Islamic perspective with particular reference to unwanted pets–stray dogs and cat

Min, M., & Zaw, C. C. (2016). Animal care: an Islamic perspective with particular reference to unwanted pets–stray dogs and cat. In: Kuala Lumpur International Islamic Studies and Civilisations (KLiISC) 2016, 7th-8th May 2016, Kuala Lumpur.

The topic of animal care especially the area of “unwanted pets in Islam” is rarely distributed among Muslim scholars,  scientists and sociologists even though animal rights movement and animal activists are obviously increased among  modern society. Small animals such as dogs, and cats have been staying together with people since the beginning of  human history. Humans have been receiving numerous benefits from them, such as keeping them as companions, using  them for hunting, house keeping, and conducting research studies. At the same time, the number of stray dogs and cats  population on the streets has increased unexpectedly nowadays, and the risk of getting injury or disease from the stray  animals becomes a huge concern for the community. Some people treated animals with cruelty, and there has been  widespread abuse of animal cases in the society. Animals are part of Allah (SWT) creations, and the Qur’an and the Al- Hadith (sayings of the prophet) prohibit cruelty to them. Islam guides us to treat animals kindly, and have mercy on  them. As Muslims, Islamic teachings and concepts should be contemplated and incorporated in our daily activities. This study was conducted with the purpose of collecting authentic guidelines regarding animal care in Islam, and exploring the view of Muslim scholars regarding animal care. The qualitative, library based approach was used as a research methodology for this study. The data were exclusively sought from books, journals, and Islamic manuscripts that were mainly based on the teachings of the Holy Qu’ran, Sunnah, and views of the Muslim scholars.The rights of animals, and
 human responsibility towards them were clearly presented from the perspectives of Islam. This study pointed out the need for maintaining balance between animal rights, and human benefits, focusing on treating animals with mercy, and reducing their sufferings even in times of killing them as a necessity. The study suggested that a need for developing a strategy by the relevant authorities regarding guidelines on some controversial issues such as animal neutering, spay, or euthanasia to reduce the problems of pet owners, as well as to prevent the dangers of zoonotic diseases in the community. This study also serves as a comprehensive overview for the readers that assist them in obtaining knowledge, and increase understanding of animal care in Islam. And it was expected to make a contribution to pet lovers in order to facilitate necessary prevention before their pets become unwanted and a burden to them.

Progress in the eradication of the feral cat and recovery of the native fauna on Socorro Is

Ortiz-Alcaraz, A., Aguirre-Muñoz, A., Arnaud, G., Galina-Tessaro, P., Rojas-Mayoral, E., Méndez-Sánchez, F., & Ortega-Rubio, A. (2017). Progress in the eradication of the feral cat (Felis catus) and recovery of the native fauna on Socorro Island, Revillagigedo Archipelago, Mexico. Therya, 8(1).

Socorro Island, in the Revillagigedo Archipelago, has the highest number of endemisms of any Mexican island. It provides habitat for 117 vascular plants, 26 % of which are endemic to the island. Also endemic to the island are one reptile and eight terrestrial bird species. However, the local ecosystem has been heavily degraded by exotic mammals over the past 140 years. The feral sheep (Ovis aries) has contributed to a 30% loss in habitat based on the island’s surface area. Another serious threat is the feral cat (Felis catus), which has severely impacted the island’s bird communities and the endemic Socorro tree lizard (Urosaurus auriculatus). Together, feral sheep and cats are responsible for the extinction in the wild of the Socorro dove (Zenaida graysoni) and the Socorro Elf Owl (Micrathene whitneyi graysoni), and pose a serious threat for other vulnerable species, such as the Townsend’s shearwater (Puffinus auricularis). The feral sheep was completely eradicated in 2012, which resulted in a rapid and remarkable recovery of the local vegetation cover. The eradication of the feral cat has been a complex issue to undertake due to the large size and topographical complexity of Socorro Island. In 2011 Grupo de Ecología y Conservacion de Islas, A. C. (GECI) started a feral cat control program, which scaled up into an eradication campaign. Here we report on the progress of the eradication campaign between 2011 and 2015, and provide a first assessment of the recovery of the native fauna. Beginning in 2011, camera traps were used to estimate cat abundance. Leg-hold and lethal traps were used to capture feral cats, some of them mounted with telemetry devices that alerted when traps were activated. Native vertebrates were monitored to confirm the positive effects derived from cat control efforts. By July 2015, 413 cats were dispatched using soft leg-hold and lethal traps, with a combined effort of 22,706 trap-nights. To date (mid-2016), cat abundance has decreased significantly, with cats being completely absent for several years in different areas of the island. The abundance of the endemic Socorro Island tree lizard and terrestrial birds has increased thanks to significant progress. Completing this important conservation action requires an increase in trapping efforts and the use of detection dogs, combined with night hunting. We estimate that the eradication of the feral cat will be completed by early 2017, after which the absence confirmation phase will begin.

Reduction in the capture success (%) of feral cats in the rainy and dry seasons from 2012 to 2015.

Optimizing an indoor lifestyle for cats

Scherk, M. (2016). Optimising an indoor lifestyle for cats. Veterinary Focus, 26(2), 2-9.

• Cats restricted to indoor living have a reduced risk for vehicular trauma, predation,
aggressive interactions with cats and other animals, and exposure to infectious diseases.
• Indoor living is not without risks.
• Not all cats can adapt readily to an indoor lifestyle, and may be at increased risk for
certain behavioral and medical problems.
• All environmental and social needs must be met for successful indoor living, and
the well-being of each cat needs to be evaluated repeatedly over time.
• Predictability, familiarity, routine and having a sense of control are key factors in
reducing stress.
• Offering outdoor access does not compensate if the cat has poor conditions indoors.