Terrestrial behavior in titi monkeys (Callicebus, Cheracebus, and Plecturocebus) : potential correlates, patterns, and differences between genera

For arboreal primates, ground use may increase dispersal opportunities, tolerance to habitat change, access to ground-based resources, and resilience to human disturbances, and so has conservation implications. We collated published and unpublished data from 86 studies across 65 localities to assess titi monkey (Callicebinae) terrestriality. We examined whether the frequency of terrestrial activity correlated with study duration (a proxy for sampling effort), rainfall level (a proxy for food availability seasonality), and forest height (a proxy for vertical niche dimension). Terrestrial activity was recorded frequently for Callicebus and Plecturocebus spp., but rarely for Cheracebus spp. Terrestrial resting, anti-predator behavior, geophagy, and playing frequencies in Callicebus and Plecturocebus spp., but feeding and moving differed. Callicebus spp. often ate or searched for new leaves terrestrially. Plecturocebus spp. descended primarily to ingest terrestrial invertebrates and soil. Study duration correlated positively and rainfall level negatively with terrestrial activity. Though differences in sampling effort and methods limited comparisons and interpretation, overall, titi monkeys commonly engaged in a variety of terrestrial activities. Terrestrial behavior in Callicebus and Plecturocebus capacities may bolster resistance to habitat fragmentation. However, it is uncertain if the low frequency of terrestriality recorded for Cheracebus spp. is a genus-specific trait associated with a more basal phylogenetic position, or because studies of this genus occurred in pristine habitats. Observations of terrestrial behavior increased with increasing sampling effort and decreasing food availability. Overall, we found a high frequency of terrestrial behavior in titi monkeys, unlike that observed in other pitheciids

GIS Risk Assessment and GAP Analysis for the Andean Titi Monkey ( Callicebus oenanthe

We conducted a predictive GIS (Geographical Information System) analysis to create a realistic Habitat Suitability Model (HSM) and risk analysis throughout the distribution of the Andean titi monkey (Callicebus oenanthe) in order to evaluate the effectiveness of the current protected area (PA) network. This was done to help current conservation work and aid in the planning and implementation of future initiatives. Little was known about this species until recently. Callicebus oenanthe is listed as Critically Endangered on the IUCN Red List of Threatened Species. It is endemic to San Martín region, northeastern Peru. Our results show that the extent of habitat available for this species may be greater than previously thought but that habitat loss in the region is extremely high. GAP analysis indicates that the current protected area network is ineffective in protecting this species, and new reserve areas are urgently needed. We recommend further study into the species' ecology to better understand its needs and to aid in future conservation work.Realizamos un análisis predictivo GIS (Sistema de Información Geográfica) para crear un Modelo de Aptitud de Hábitat (HSM) realista y un análisis de riesgo a lo largo de la distribución del mono tití andino (Callicebus oenanthe) para evaluar la efectividad del área protegida (AP) actual. red. Esto se hizo para ayudar al trabajo de conservación actual y ayudar en la planificación e implementación de iniciativas futuras. Poco se sabía de esta especie hasta hace poco. Callicebus oenanthe figura como En Peligro Crítico en la Lista Roja de Especies Amenazadas de la UICN. Es endémica de la región de San Martín, noreste del Perú. Nuestros resultados muestran que la extensión del hábitat disponible para esta especie puede ser mayor de lo que se pensaba anteriormente, pero que la pérdida de hábitat en la región es extremadamente alta. El análisis de GAP indica que la red actual de áreas protegidas es ineficaz para proteger a esta especie, y se necesitan con urgencia nuevas áreas de reserva. Recomendamos más estudios sobre la ecología de la especie para comprender mejor sus necesidades y ayudar en el trabajo de conservación futuro