Use of spatial capture–recapture to estimate density of Andean bears in northern Ecuador

By: , and 



The Andean bear (Tremarctos ornatus) is the only extant species of bear in South America and is considered threatened across its range and endangered in Ecuador. Habitat loss and fragmentation is considered a critical threat to the species, and there is a lack of knowledge regarding its distribution and abundance. The species is thought to occur at low densities, making field studies designed to estimate abundance or density challenging. We conducted a pilot camera-trap study to estimate Andean bear density in a recently identified population of Andean bears northwest of Quito, Ecuador, during 2012. We compared 12 candidate spatial capture–recapture models including covariates on encounter probability and density and estimated a density of 7.45 bears/100 km2 within the region. In addition, we estimated that approximately 40 bears used a recently named Andean bear corridor established by the Secretary of Environment, and we produced a density map for this area. Use of a rub-post with vanilla scent attractant allowed us to capture numerous photographs for each event, improving our ability to identify individual bears by unique facial markings. This study provides the first empirically derived density estimate for Andean bears in Ecuador and should provide direction for future landscape-scale studies interested in conservation initiatives requiring spatially explicit estimates of density.

Publication type Article
Publication Subtype Journal Article
Title Use of spatial capture–recapture to estimate density of Andean bears in northern Ecuador
Series title Ursus
DOI 10.2192/URSU-D-16-00030.1
Volume 28
Issue 1
Year Published 2017
Language English
Publisher International Association for Bear Research and Management
Contributing office(s) Coop Res Unit Leetown
Description 10 p.
First page 117
Last page 126
Country Ecuador
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