Andean bear (Tremarctos ornatus) population density and relative abundance at the buffer zone of the Chingaza National Natural Park, cordillera oriental of the colombian andes

Abstract

The Andean bear (Tremarctos ornatus) population density and relative abundance within the Chingaza Massif were assessed between September 2015 and May 2016. One hundred seventeen (117) camera traps were installed at 9 grids: 13 cameras per grid, each camera separated 750 m from the other; the sampling effort was 17,057 days-trap. Two thousand seven hundred eighty-four (2,784) native fauna records were obtained, 1,456 corresponding to mammals, 183 records for Andean bear specimens, 158 of them independent bear records (at least one hour between records), and 106 effective-independent bear records (also permitting individual recognition). Fifty-seven (57) Andean bear individuals were identified according to key external morphological features. Sixteen (16) adults were recaptured (12 males and 4 females), with a maximum mean distance of 27.22 km. Bears population density was 2.9 bears per 100 km². Based on this density and the buffer area of the sampling grids, we estimated an overall number of 122 bears in 4,215.15 km². The estimated density is the first for the species in Colombia and the lowest regarding previous reports from other countries. Thus, it is necessary to better understand how integral habitat quality and the anthropic impacts on habitat quality, availability, and connectivity may affect the Andean bear population densities in Colombia, as a useful tool for assessing populations` state and focus future conservation actions.

Multispecies facial detection for individual identification of wildlife: a case study across ursids

“…Within the Ursidae, the presence of distinguishing marks varies by species; Andean bears, Asiatic black bears, sun bears, and to some extent giant pandas Ailuropoda melanoleuca, generally possess varied markings on the face or chest that human observers have used for visual identification of individuals (Higashide et al 2012;Ngoprasert et al 2012;Zheng et al 2016;Molina et al 2017;Appleton et al 2018;Rodríguez et al 2020;Morrell et al 2021), whereas American black bears U. americanus, brown bears U. arctos, polar bears U. maritimus, and sloth bears generally do not (although see Shimozuru et al 2017). However, there is concern regarding the standardization of manual individual ID approaches across different researchers, for wildlife with and without distinguishing markings (Choo et al 2020;Johansson et al 2020).…”

Space use by a male Andean bear (Tremarctos ornatus) tracked with GPS telemetry in the Macizo Chingaza, Cordillera Oriental of the Colombian Andes

“…Places with less natural coverage demand greater movements to obtain enough resources, leading to larger home ranges (Ofstad et al 2016). The Chingaza massif is characterized by high-impact human activities at the landscape level, including significant land cover transformation to croplands and livestock pastures, along with the infrastructure construction (i.e., main roads, dams, mines) in and around the massif, which have drastically transformed the natural areas (Rodríguez et al 2020).…”