Characterization of Jaguar Utilization Distributions in the Brazilian Pantanal

Abstract

Jaguars (Panthera onca) have been eradicated from 50% of their historical range across Mexico, Central America, and South America. The Brazilian Pantanal in west-central Brazil represents a stronghold of core habitat for the species and is an important site for conservation. Habitat in the Pantanal is threatened largely due to expanding human activity causing habitat loss and fragmentation, making remaining habitat vitally significant. This study seeks to characterize the utilization distributions of jaguars in the area to better understand the habitat use and spatial ecology of a threatened species. GPS locations taken from 13 jaguars were used to calculate estimates of kernelhomesrangesatthe50% (core range)and 95% (home range)isopleth levels. These ranges were used to quantify habitat use in relation to land cover types. Patterns of distribution heavily followed waterways, perhaps following that of their main prey,caimans(Caiman crocodilus yacare). Wetlands were the most heavily utilized among all jaguars at the 95% home range followed by grasslands. However, at the 50% core range level there was a shift in greater utilization of forest habitat over grassland. Additionally, females generally had smaller home ranges than that of males and exhibited less overlap between home ranges(27 km2) than between male home ranges(217 km2) – a key indicator of female spatial avoidance.