Estimating Population Density of Neotropical Terrestrial Mammals in Human-Altered Environments Based on Camera-Trapping and Secondary Data on Home Range

Abstract

Wildlife abundance estimates can be necessary to understand ecological processes that determine the patterns of diversity, crucial to monitoring programs. Human-modified environments, such as agricultural and silvicultural landscapes can act as a complement to conservation units (e.g., National Parks), despite their numerous environmental impacts. In this study we estimated population densities (ind.km−2) of medium to large terrestrial mammals in a silvicultural landscape in southeast Brazil, based on a combination of camera-trapping and home range data from literature review with the following results: Mazama gouazoubira (0.06), Pecari tajacu (0.94–1.31), Sus scrofa (0.06–0.09), Cerdocyon thous (0.06), Chrysocyon brachyurus (0.03–0.06), Leopardus guttulus (0.06), Puma concolor (0.03–0.06), Eira barbara (0.03), Nasua nasua (0.94–1.88), Cabassous unicinctus (0.09), Dasypus novemcinctus (0.13), Lepus europaeus (0.09), Sylvilagus brasilien-sis (0.01–0.03), Mymercophaga tridactyla (0.09–0.13), Tamandua tetradactyla (0.09), and Cuniculus paca (0.03). These estimates are similar to previous studies on Neotropical canids and felids, even those carried out in pristine environments, but species with smaller home-ranges appear to be underestimated. The present results indicate that the methodology is applicable to wildlife monitoring in human-altered environments, especially agricultural/silvicultural landscapes, in which environ-mental certification requires periodical wildlife surveys. Future studies should prioritize local estimates of species home-range and habitat use, as well as the sampling design and effort to improve species detectability.