House Cat Felis Catus Research Articles

Diet of the feral cat, Felis catus, in central Australian grassland habitats during population cycles of its principal prey

Foraging theory predicts that animals should forage so as to maximize their net rate of energy gain or to minimize their risk of starvation. In situations where prey numbers fluctuate dramatically, theory predicts further that foragers will eat ‘optimal’ prey when it is abundant but expand their diet to include other prey types when the optimal prey is scarce; this is the alternative prey hypothesis. Here, we test this prediction by analyzing the diet of a mammalian predator, the feral house cat Felis catus, during periods of scarcity and abundance of the long-haired rat Rattus villosissimus. We also investigate whether the body condition of feral cats differs during different stages of the prey population cycle. Feral cats were shot during culling operations in semi-arid grassland habitats in central Queensland, Australia, and the stomach contents later identified. We found that the body condition of feral cats did not differ between phases of the prey population cycle, but the diets of cats culled when long-haired rats were scarce were significantly more diverse than when this rodent was abundant. Rats comprised about 80 % of cats’ diet by volume and frequency of occurrence when they were present, whereas birds, reptiles and invertebrates comprised the bulk of the diet when rats were not available. We conclude that, whilst feral cats are often thought to be specialist predators, they may be better considered as facultative specialists that will shift their diet in predictable ways in response to changes in the abundance of primary prey.

Individual hunting behaviour and prey specialisation in the house cat Felis catus: Implications for conservation and management

Predators are often classed as prey specialists if they eat a narrow range of prey types, or as generalists if they hunt multiple prey types. Yet, individual predators often exhibit sex, size, age or personality-related differences in their diets that may alter the impacts of predation on different prey groups. In this study, we asked whether the house cat Felis catus shows individuality and specialisation in its hunting behaviour and discuss the implications of such specialisation for prey conservation and management. We first examined the prey types killed by cats using information obtained from cat owners, and then presented data on cat hunting efficiency on different prey types from direct observations. Finally, we quantified dietary shifts in cats when densities of their preferred prey varied. Twenty-six cats that returned 10 or more prey items to their owners showed marked differences in prey preferences (P<0.001), with eight cats specialising on small birds, five on lizards, four on black rats Rattus rattus, three on large birds, and six returning multiple prey types. Observations of 182 hunting attempts by 15 cats showed significantly high hunting efficiency (P<0.05) by four cats on rodents (83–100% of attacks on rodents were successful) and by one cat on rabbits Oryctolagus cuniculus (94% attack success), whereas 10 cats hunted two or three prey types with similar efficiency. At two field sites where rabbits were preferred cat-prey, the percentage of rabbit in the diet of cats showed quadratic relationships against rabbit density, with cats consuming rabbits when they were undetected in surveys. Our results suggest that cats can exhibit individual, or between-phenotype, variation in hunting behaviour, and will hunt specific prey types even when these prey become scarce. From a conservation perspective, these findings have important implications, particularly if cats preferentially select rare or threatened species at times when populations of these species are low. Determining whether prey specialisation exists within a given cat population should therefore be useful for assessing the likely risk of localised prey extinctions. If risks are high, conservation managers may need to use targeted measures to control the impacts of specialist individual cats by using specific baits or lures to attract them. We conclude that individuality in hunting behaviour and prey preference may contribute to the predatory efficiency of the house cat, and suggest that studies of the ontogeny and maintenance of specialist behaviours be priorities for future research.

Diet of the feral cat, Felis catus, in central Australian grassland habitats: do cat attributes influence what they eat?

The house cat Felis catus was introduced to Australia as a pet and means of rodent control over 200 years ago, but now has established feral populations and has become a serious threat to native wildlife. Using stomach content analysis of 73 feral cats from semi-arid grassland habitats in Queensland, Australia, we aimed to identify dominant prey groups in the cats' diet and to explore associations between the diversity of prey eaten and attributes of the cats including body size, condition, sex, age and coat colour. We also sought to determine any relationships between cat size and the size of the dominant prey in the diet, the long-haired rat Rattus villosissimus. Mammals and reptiles were the dominant prey, with R. villosissimus occurring in 60 % of samples and comprising more than half of all prey by volume. Birds and terrestrial invertebrates were the next most important contributors to the diet, but fish, frogs and freshwater crustaceans also were surprisingly well represented. The dietary diversity of cats was largely unrelated to any of the cat attributes that we measured, although a positive relationship emerged between cat head width and the range of prey types eaten. Our study was conducted during a population irruption of R. villosissimus and confirms that cats are able to exploit an abundant focal prey resource when the opportunity occurs. Further research now is needed to explore associations between diet and cat attributes during periods when rats are scarce.

Blandowski’s mammals: Clues to a lost world

Wilhelm Blandowski was the first zoologist employed by the Victorian Government, being appointed Officer of the Museum of Natural History by Governor La Trobe on 1 April 1854. Although he remained in this position for less than four years he left an important legacy by beginning the documentation of Victoria’s mammalian fauna before the full impact of European pastoralism and feral animals had become apparent. In particular, the 1856-57 zoological survey expedition to the lower Murray-Darling region provided a unique insight into the mammalian community that existed there before European occupation triggered a sudden decline in mammal species diversity, as happened progressively across the southern two thirds of Australia over the subsequent 90 years. Of the 34 mammal taxa recorded by the Blandowski Expedition, ten are extinct, nine no longer occur in the region, four are still present but with greatly reduced and fragmented distributions, seven have broad distributions in the region little changed since Blandowski’s time, although severely fragmented, and the remaining four have probably expanded their distributions. The contributions of Blandowski and his assistant Gerard Krefft to our understanding of the nature and causes of these mammal declines are examined and discussed. Unfortunately, the surviving contemporary documentation of the Expedition and the associated specimens is inadequate to shed much light on the factors that triggered the initial mammal declines, but the results do not support recent suggestions that predation by the introduced house cat Felis catus was pivotal.

Trends in the prey size‐based trophic niches of feral and House Cats Felis catus L.

House Cats Felis catus L., whether attached to human households or not, appear to be versatile opportunistic predators. Their principal prey in most areas are mammals (rodents and rabbits), with bird prey secondary. Trophic niche breadth, as measured by the standard deviation of the spectrum of logarithmically transformed prey sizes (‘SLH’), shows a latitudinal trend, being greater in low latitudes: it is also greater in periods of high prey availability. This appears to be influenced by inclusion of very small prey, especially insects, in areas and seasons when they are available. Both the niche breadth and the mean prey size (niche position) appear to be constant as population mean cat size increases. The most common prey size for cats is about 1% of their own body weights, which is much less than most previously reported values for carnivores.