Feeding and Spatial Ecology of Felis geoffroyi in Southern Patagonia

Abstract

Geoffroy's cat (Felis geoffroyi) is distributed from southern Bolivia and the Parana Basin of southern Brazil to the southern tip of Patagonia in Chile and Argentina (Cabrera, 1957; Ximenez, 1975). In 1980, this spotted cat became the most commonly traded felid species in the world (MacMahan, 1986) with more than 450,000 skins exported from 1976 to 1980 from Argentina alone (Fujita and Calvo, 1982). Despite its economic importance, almost nothing is known about the biology and ecology of the species, especially in its native South American habitat. In Chile, where Geoffroy's cat is classified as endangered, research on this species is considered to be a priority (Glade, 1988). The only published field study was the report of the home range of one subadult female in Paraguay based on 12 radiotelemetry relocations (Berrie, 1978). The goal of our study was to obtain basic ecological information on Geoffroy's cat in the southern portion of its distribution. Specific objectives were to describe home-range sizes and distribution patterns, habitat use, activity patterns, and food habits of Geoffroy's cat. The study was conducted from 1986 through 1989 in the eastern part of Torres del Paine National Park (51*3'S, 72*55'W), an International Man and Biosphere Reserve located in the eastern foothills of the Andean mountain range in southern Chile. The park encompasses 2,400 km2 and provides almost undisturbed habitat for wildlife. The park has a high heterogeneity of plant associations and habitats from glacier-covered mountains to dense Nothofagus deciduous forest and grassland. Approximately 70% consists of a steppe biome, or pre-Andean, dry-shrub association, and the remainder is a mosaic of lakes, forests, and aridmountain alpine zones. The steppe is characteristic of the pampa of southern South America, found in Chile and Argentina at elevations <500 m (Pisano, 1973, 1974). The locally dominant species of this biome (or association) is mata barrosa (Mulinum spinosum), a spiny, dome-shaped shrub, common in thin, rocky upland, and rapidly draining soils and mata negra (Verbena tridens), a 1to 1.5-m shrub covering large areas. Other common species are senecio (Senecio patagonicus), calafate (Berberis buxifolia), and paramela (Adesmia boronoides). The woodland areas are dominated by two medium-sized species of trees, fiirre (Nothofagus antarctica) and lenga (N. pumilio). The dominant grass species in the study area are Festuca gracillina, Anarthrophyllum patagonicum, and F. palliscens, in order of decreasing cover (Ortega and Franklin, 1988; Pisano, 1973, 1974; Texera, 1973). The park has a high diversity of mammalian species (Johnson et al., 1990). Potential mammalian prey species included the introduced European hare (Lepus capensis) and several cricetine rodents such as Auliscomys micropus, Oryzomys longicaudatus, Phyllotis darwini, Reithrodon physodes, and several species of Akodon. Numerous avian species also were potential prey items for Geoffroy's cat, such as the upland goose (Chloephaga picta), austral parakeet (Enicognathus ferrugineus), and eared dove (Zenaida auriculata). The puma (Felis concolor), culpeo fox (Dusicyon culpaeus), chilla fox (D. griseus), Patagonia hog-nosed skunk (Conepatus humboldtii), Patagonia weasel (Lyncodon patagonicus), and several raptors, including the great-horned owl (Bubo virginianus) and black-chested buzzard-eagle (Geranoaetus melanoleucus), were potential competitors. There are two general climatic periods, a relatively cold, dry, typically windless season from May through September (July mean temperature = 0.20C) and a relatively warm, windy, rainy season from October through April (January mean temperature = 12.60C). Mean annual precipitation is 550 mm, with 60% falling from January to May (Pisano, 1974). Adjacent mountains and ice fields create local weather patterns as reflected by a large variability in precipitation (Pisano, 1974). Geoffroy's cats were captured either in padded leg-hold traps (Victor no. I1? soft-catch coil spring) or in trees by use of trained hunting dogs and immobilized with ketamine hydrochloride (Ramsden et al., 1976)