Browsing by Autor "Wallace, Robert B"

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Ecological and Behavioural Factors Influencing Territorial Call Rates for the Bolivian Titi Monkeys, Plecturocebus modestus and Plecturocebus olallae.
(2016) Martinez, Jesus; Wallace, Robert B
Primate territorial calls have been used to locate groups in censuses. Daily variations in call rates are a potential source of error in these studies. To obtain more accurate estimations of population density it is necessary to determine how much variation there is in group call rates and to identify the factors that influence them. We present data on the emission of territorial calls by two threatened and endemic titi monkeys in Bolivia: Plecturocebus olallae and P. modestus. We found interspecific differences in daily call rates (52% P. modestus and 33% P. olallae). Groups inhabiting more continuous forests vocalized more frequently than groups in fragmented forests, which might be linked to the higher abundance of groups in less fragmented forests. We found seasonal differences in call rates between species, with more frequent calling in P. modestus during the dry season, while P. olallae called more frequently in the rainy season. The study groups emitted territorial calls mostly from the central zones of their territories, suggesting they do not face intense spatial competition with neighbouring groups. Our results improve the general ecological knowledge on P. olallae and P. modestus, and can also be used to improve population abundance studies and ongoing conservation efforts.
Small Felids Coexist in Mixed-Use Landscape in the Bolivian Amazon.
(2024) Anderson, Courtney; Zuckerwise, Amelia; Wallace, Robert B; Ayala, Guido; Viscarra, Maria; Schmitz, Oswald J
In the face of global species loss, it is paramount to understand the effects of human activity on vulnerable species, particularly in highly diverse, complex systems. The Greater Madidi Landscape in the Bolivian Amazon includes several biodiverse protected areas that were created with the goal of sustaining healthy and diverse ecosystems while not impeding the livelihoods of local indigenous peoples. In this study, we sought to use camera trap data and single-species occupancy analysis to assess the impacts of different forms of human activity on four species of small felids: ocelots (Leopardus pardalis), margays (Leopardus wiedii), jaguarundi (Herpailurus yagouaroundi), and oncilla (Leopardus tigrinus). We modeled both human variables (proximity to indigenous communities, roads, and tourist camps) and non-human variables (terrain ruggedness, proximity to rivers, canopy height, prey availability, and large cat abundance). Margay occupancy was unaffected by any of these human variables and ocelots showed only weak evidence of being affected by tourism. Ocelots were particularly pervasive throughout the study area and were consistently estimated to have high occupancy probability. We did not obtain sufficient data on jaguarundi or oncilla to reliably model these effects. Our results indicate that small cats successfully coexist both with each other and with the surrounding human activity in this unique landscape, which serves as a model for global protected area management.