Movement Patterns of Jaguar

Abstract

Jaguar on two small ranches in southwestern Brazil had a density of about one animal per 25 sq km. Females ranged over at least 25-38 sq km and males over twice that much terrain. The ranges of females overlapped, and the range of a resident male included the ranges of several females. Jaguar and puma ranges also overlapped, but each species favored parts not much used by the other. Day-and-night radio tracking revealed precise travel and activity patterns of two female jaguar. The social system of jaguar is in most respects similar to that of other large solitary cats such as puma, leopard, and tiger. As PART OF A WILDLIFE STUDY in the Pantanal region of Mato Grosso, Brazil, we collected information on jaguar (Parnthera onca). Data were gathered intermittently between April 1977 and September 1978 on the Acurizal and Bela Vista ranches (17?45'S, 57?37'W) at the western edge of the Pantanal, a vast swampy plain near the Bolivian border. During 1977 we assessed the impact of jaguar predation on a prey population (Schaller and Vasconcelos 1978) and deduced movement patterns from spoor; during 1978 we radio-tracked two jaguars. Ranch hands on Acurizal shot two of the study animals, and this action prematurely terminated our research there. Because jaguar literature is based mainly on anecdotal accounts by hunters and naturalists (see Guggisberg 1975), our preliminary findings contribute a more substantial understanding of the species and provide data for comparison with information available on other large, solitary cats (Hornocker 1969, Muckenhirn and Eisenberg 1973, McDougal 1977). STUDY SITE The Acurizal ranch, 137 sq km in size, consists of a strip of land, 24 km long and 5-10 km wide, between the Paraguay River and the crest of the Serra de Amolar which at its northernmost point ceases abruptly at the shore of Lake Gaiba. Two broad valleys, named here the First and Second valleys, cut into the range (fig. 1). Three kilometers north of Acurizal, across Lake Gaiba, is Bela Vista, an island of about 90 sq km, its size varying somewhat with the water