The cats of Herekopare

Fitzgerald, B. M., & Veitch, C. R. (1985). The cats of Herekopare Island, New Zealand; their history, ecology and affects on birdlife. New Zealand Journal of Zoology, 12(3), 319-330.

House cats (Felis catus) were introduced to Herekopare Island, a mammal-free island of about 28 ha near Stewart Island, in about 1925. In winter 1970, the total population of 33 cats (20 males, 13 females) — a density of 1.2 cats/ha — was killed, mainly by trapping. Examination of stomach contents and scats showed that the cats fed mainly on petrels, supplemented by land birds and insects. The bird life of Herekopare Island was studied by H. Guthrie-Smith in 1911, L. E. Richdale in the early 1940s, and by New Zealand Wildlife Service staff in 1968 and 1970. Their accounts indicate that a vast breeding population of diving petrels and thousands of broad-billed prions were probably exterminated by the cats, though fairy prions and sooty shearwaters persisted. Among land birds, the yellow-crowned parakeet, robin, fernbird, brown creeper, Stewart Island snipe, and banded rail were exterminated. Two other species, the red-crowned parakeet and tomtit, probably disappeared but subsequently recolonised the island. Although cats had the greatest influence on the bird life over this period, wekas, which were present for some years, together with changes in the vegetation, may have affected some bird populations.

Artificial nest predation in forest tracts and its relationshib with the decline of birds

Wilcove, D.S. 1985. Nest predation in forest tracts and the decline of migratory songbirds. Ecology 66: 1211- 1214

Nest predation has been suggested as an important cause of the decline of breeding populations of migratory songbirds in small woodlots in eastern North America. I tested this hypothesis by placing artificial nests with fresh quail eggs in forest of different sizes in Maryland and Tennessee. Predation rates were higher in small woodlots than in large tracts. Predation was especially intense in woodlots near suburban neighborhoods compared to woodlots in isolated rural areas. Experimental open—cups nests were move vulnerable to predators when placed on the ground vs. 1—2m above ground. In either position these open—cup nests were move vulnerable to predators than experimental cavity nests. Since most species of migratory songbirds construct open—cup nests, and several species place them near the ground, migratory songbirds should by strongly affected by higher predation rates in small forest tracts

Spacing patterns in a urban cat population in Italy

Natoli, E. (1985). Spacing pattern in a colony of urban stray cats (Felis catus L.) in the historic centre of Rome. Applied Animal Behaviour Science,14(3), 289-304.

Factors controlling the spatial organization of a colony of stray cats (Felis catus Linnaeus, 1758) in an urban environment were investigated. Neighbouring colonies of stray cats were also observed, but in less detail. The findings were that:

(1) the animals of the colony selected for intensive study showed an active spacing pattern, i.e. they were not randomly distributed within the boundaries of the study area;

(2) the existence of an active spacing pattern was related to the resources offered by the environment where the animals lived;

(3) these resources (food and shelter) were concentrated in some parts of the study area. Consequently, the animals used these parts more intensively than others. The observations carried out on neighbouring colonies of cats confirmed the results reported for the colony examined in detail.

Some workers consider domestic cats to be a unique resource for evolutionary studies of social behaviour because it has been shown that this species has a high degree of intra-specific variation of behaviour in contrasting habitats. The object of this study was to examine the spacing behaviour and the evolution of the domestic cat social system as a response to a particular urban environment.

Spacing pattern in urban cats in Italy

Natoli, E. (1985). Spacing pattern in a colony of urban stray cats (Felis catus L.) in the historic centre of Rome. Applied Animal Behaviour Science,14(3), 289-304.

Factors controlling the spatial organization of a colony of stray cats (Felis catus Linnaeus, 1758) in an urban environment were investigated. Neighbouring colonies of stray cats were also observed, but in less detail. The findings were that:

(1) the animals of the colony selected for intensive study showed an active spacing pattern, i.e. they were not randomly distributed within the boundaries of the study area;

(2) the existence of an active spacing pattern was related to the resources offered by the environment where the animals lived;

(3) these resources (food and shelter) were concentrated in some parts of the study area. Consequently, the animals used these parts more intensively than others. The observations carried out on neighbouring colonies of cats confirmed the results reported for the colony examined in detail.


Some workers consider domestic cats to be a unique resource for evolutionary studies of social behaviour because it has been shown that this species has a high degree of intra-specific variation of behaviour in contrasting habitats. The object of this study was to examine the spacing behaviour and the evolution of the domestic cat social system as a response to a particular urban environment.

Biology of feral cats on Macquarie

Brothers, N. P., Skira, I. J., & Copson, G. R. (1985). Biology of the feral cat, Felis catus (L.), on Macquarie Island. Wildlife Research, 12(3), 425-436.

A feral cat roams among baby penguins on Macquarie Island.
Photo: Geoff Copson/ Tasmanian NPWS

246 feral cats were shot on Macquarie Island, Australia, between Dec. 1976 and Feb. 1981. The sex ratio ( males : females ) was 1:0.8. The percentages of animals with tabby, orange and black coats were 74, 26 and 2 resp. [sic]. Of the 64 orange cats, 56 were males . The breeding season was Oct.-Mar., with a peak in Nov.-Dec. The number of embryos in the 14 pregnant females averaged 4.7 (range = 1-9). The size of the 23 litters that were observed averaged 3 (range = 1-8). Kitten survival to 6 months of age was estimated to be <43%.

More on Macquarie island cats

Free ranging domestic cats' demography

Warner, R. E. (1985). Demography and movements of free-ranging domestic cats in rural Illinois. The Journal of wildlife management, 49(2): 340-346.

Free-ranging domestic cats on farmsteads were censused annually in August 1977-81 within a 5,182-ha area typical of the cash-grain region in central Illinois. The estimated average number of cats on the area in late summer was 326 (6.3/100 ha). Annual recruitment of immature cats into the late summer population averaged 1.5/adult female. Survival beyond 3-5 years of age was rare; <1% survived 7 or more years. Eleven adult cats were radio-monitored during a 30-day period in summer; four males ranged over larger areas (P < 0.01) than seven females (228 ± 100 ha and 112 ± 21 ha, respectively). When cats were not on farmsteads, approximately 73% of their radiolocation points (N = 1,227) were in edge or linear configurations of cover. Cats made disproportionately high (P < 0.05) use of farmsteads and perimeters, roadsides, and field interfaces and disproportionately low use (P < 0.05) of fields of corn and soybeans. Domestic cats on the area were well fed by humans but routinely deposited prey at their residences.