Social behaviour in a large multi-male cat colony

Natoli, E., & De Vito, E. (1991). Agonistic behaviour, dominance rank and copulatory success in a large multi-male feral cat, Felis catus L., colony in central Rome. Animal Behaviour, 42(2), 227-241.

The mating strategies of male and female feral cats living in a large urban colony were analysed. The distribution of males around the female being courted, the agonistic and copulatory behaviour patterns of 19 males belonging to the group studied and the copulatory behaviour of 15 females of the same group, were investigated. A linear dominance hierarchy based on the outcome of agonistic encounters was found among males. It did not correlate with copulatory success. Courting males did not fight around the female in oestrus. The optimal mating strategies of male and female cats conflict: females would do best to copulate with more than one male, whereas males should monopolize the female and guard her from other males. In this study, however, females mated polygamously but males did not attempt to monopolize females. Possible explanations for this obscure male behaviour are given.

Impact of introduced predators, including dogs and cats, on island reptiles

Case, T. J., & Bolger, D. T. (1991). The role of introduced species in shaping the distribution and abundance of island reptiles. Evolutionary Ecology, 5(3), 272-290.

Species interactions, as revealed by historical introductions of predators and competitors, affect population densities and sometimes result in extinctions of island reptiles. Mongoose introductions to Pacific islands have diminished the abundance of diurnal lizards and in some cases have led to extinctions. Through these population level effects, biogeographic patterns are produced, such as the reciprocal co-occurrence pattern seen with the tuatara and its predator, the Polynesian rat, and with the tropical gecko competitors Hemidactylus frenatus and Lepidodactylus lugubris in urban habitats in the Pacific. Although competition has led to changes in abundance and has caused habitat displacement and reduced colonization success, extinctions of established reptile populations usually occur only as a result of predation.

These introductions, along with many manipulative experiments, demonstrate that present day competition and predation are potent forces shaping community structure and geographic distributions. The human introduction of species to islands can be viewed as an acceleration of the natural processes of range expansion and colonization. The immediate biotic consequences of these natural processes should be of the same intensity as those of the human introductions. Coevolution may subsequently act to ameliorate these interactions and reduce the dynamical response of one species to the other. The role played by coevolution in mediating interactions between competitors and predator and prey is highlighted by the susceptibility of predator-naive endemic species to introduced predators and the invalidity of species-poor communities.

Recovery of seabirds after cat control

Cooper J. & A. Fourie. 1991. Improved breeding success of great-winged petrels Pterodroma macroptera following control of feral cats Felis catus at subantarctic Marion Island. Bird Conservation International, 1:171-175.

A population of feral domestic cats Felis catus has existed at subantarctic Marion Island since 1951. From 1977 to 1990 an ongoing programme has utilized an introduced disease, shooting and gin-trapping in an endeavour to control cat numbers, with the eventual aim of their eradication. Burrowing petrels (Procellariidae) form the majority of the cats' diet. The breeding success of the winter-breeding Great-winged Petrel Pterodroma macroptera has varied between nil and 20.5% in the period from 1979 to 1984, due primarily to cat predation of chicks causing up to 100% mortality. In 1990, by which time cat numbers had been greatly reduced from their 1970s' peak, Great-winged Petrels had a breeding success of 59.6%, with chick mortality being zero. No signs of cat predation were observed. This finding provides good reason to continue the control programme until cats are finally eradicated from Marion Island.

Cats' diet on some Pacific islands

Jarvis and Howlnad

R.D. Kirkpatrick and Mark J. Rauzon. 1986. Foods of Feral Cats Felis catus on Jarvis and Howland Islands, Central Pacific Ocean. Biotropica, 18 (1): 72-75

Food habits of feral cats (Felis catus) were studied on two small uninhabited islands in the central Pacific Ocean. Cat stomach contents, collected on Howland Island in May 1979 and on Jarvis Island during May 1979 and June-July 1982, revealed that sooty terns (Sterna fuscata) were the primary prey species. Other seabirds, lizards, insects and, on Jarvis Island, house mice were also eaten. Fetal cats may have virtually exterminated the wedge-tailed shearwater colony on Jarvis Island.

Kermadec
Fitzgerald, B.M.; Kark, B.J. & Veitch, C.R. 1991. The diet of feral cats (Felis catus) on Raoul Island, Kermadec Group. New Zealand Journal of Ecology 15(2): 123-129.

Feral cats became established on Raoul Island some time between 1836 and 1872; the prey available to them included a great variety of nesting seabirds, few of which are present now, landbirds and kiore (Rattus

exulans). Norway rats reached the island in 1921, providing additional prey for cats, but also another potential predator of seabirds. The diet of cats is described from guts and scats collected between 1972 and 1980. Rats are the main food, with land birds second in importance, and seabirds are now a minor item. More than 90% of the rats eaten by cats are kiore although more Norway rats than kiore are trapped. Eradicating cats from Raoul Island is feasible but because Norway rats too are important predators of birds on islands, it is likely that eradicating cats without also eradicating Norway rats will do little to restore the diversity of bird species on Raoul Island, although the densities of a few species now present might be increased.

Hawai'i
Hess, S. C.; Hansen, H.; Nelson, D.; Swift, R. & Banko, P. C. 2007. Diet of feral cats in Hawai'i Volcanoes National Park. Pacific Conservation Biology, 13: 244–249.

We documented the diet of feral cats by analysing the contents of 42 digestive tracts from Kilauea and Mauna Loa in Hawai'i Volcanoes National Park. Small mammals, invertebrates, and birds were the most common prey types consumed by feral cats. Birds occurred in 27.8-29.2% of digestive tracts. The total number of bird, small mammal, and invertebrate prey differed between Kilauea and Mauna Loa. On Mauna Loa, significantly more (89%) feral cats consumed small mammals, primarily rodents, than on Kilauea Volcano (50%). Mice (Mus musculus) were the major component of the feral cat diet on Mauna Loa, whereas Orthoptera were the major component of the diet on Kilauea. We recovered a mandible set, feathers, and bones of an endangered Hawaiian Petrel (Pterodroma sandwichensis) from a digestive tract from Mauna Loa. This specimen represents the first well-documented endangered seabird to be recovered from the digestive tract of a feral cat in Hawai'i and suggests that feral cats prey on this species.

Smucker, T. D., G. D. Lindsey, & S. M. Mosher. 2000. Home range and diet of feral cats in Hawaii forests. Pacific Conservation Biology 6: 229–237.

Feral cat Felis catus home range in a Hawaiian montane wet forest and their diet in three habitats - montane wet forest, subalpine dry forest, and lowland dry forest - were determined to provide baseline ecological data and to assess potential impacts to native terrestrial fauna. Seven cats (three males and four females) were captured in 624 trap nights. Mean weight of adult cats was 2.85 0.27 (SE) kg for males and 1.87 0.03 kg for females. Mean diurnal home range using the adaptive kernel method was 5.74 2.73 km² for three males and 2.23 0.44 km²  for two females. Daytime locations were always within the montane wet forest with the borders on one or more sides of the home ranges of all cats defined by open grassland pastures. Rodents comprised the majority of the cat diets in all three habitats, with the frequencies of occurrence between 0.88 and 0.91. Bird remains were a regular component of the diet of cats, with montane wet forest having the highest frequency of occurrence (0.68), followed by subalpine dry forest (0.53). and lowland dry forest (0.21).

Loss of wildlife to domestic cats

Paton, D. (1991). Loss of wildlife to domestic cats. In Potter, C. (ed), The Impact of Cats on Native Wildlife: Proceedings of a Workshop held on May 8-9 1991. ANPWS, Canberra

Questionnaires asked people how many animals they thought their cat(s) had killed in the previous 12 months. Of the 3000 questionnaires distributed, 709 were returned, covering 700 cats in Adelaide suburbs, in country towns and in rural areas. The majority of the questionnaires (88%) came from members of birders' associations.

• Cats in rural areas were reported to catch over twice as many prey as suburban cats. 
• The average number of prey reported caught per year was 30. 
• Suburban cats (the majority of cats) were reported to catch less, and rural cats (far fewer in number) caught more. 
• Bells were ineffective 
• Most preys were non native