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 We collated published and unpublished data from 86 studies across 65 localities to assess titi monkey (Callicebinae) terrestriality.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

The Ecology and Behavior of the Rio Mayo Titi Monkey (Callicebus Oenanthe) in the Alto Mayo, Northern Peru

I document the behavior and ecology of a small pair-bonded primate, the Río Mayo or Andean titi monkey ( Callicebus oenanthe ). This is the first long-term field study on this endangered primate. Research was conducted in a 3-hectare forest patch found near the Río Mayo, San Martin, Peru, at 890 meters a.s.l. The study group, consisting of an adult pair and two offspring, was observed for over 800 hours from January to August 2005 using instantaneous focal sampling. The titi monkeys spent a majority of the time acquiring and ingesting fruits and insects (\u3e80%), with lesser portions of leaves, tendrils, meristems, flowers, and young seeds. Few fruit species contributed to the majority of the fruit diet, and 1 to 2 species made up the majority of the diet per month. Time devoted to insect foraging represented a considerable portion of daily activity budget (17%). C. oenanthe is mainly an investigative forager of immobile insects and spiders but also opportunistically caught fast-moving insects and fed on mass congregations of insects. During resource scarcity C. oenanthe switched its diet to mostly insects and flowers, used different plant parts, and relied on plant resources that were either common in disturbed forest habitat or were available for extended periods of time, such as fruits from semi-parasitic mistletoes. The female consumed more insects than the male, especially during lactation. The male spent the majority of time resting, and resting increased significantly during the infant carrying period. Although the male and female exhibited characteristics typical of a strong pair bond, the male contributed more to grooming bouts, was responsible for a greater proportion of contacts made, and closely followed the female more than the reverse. Sex differences in energetic requirements as seen by differences in the amount and type of insect foraging and activity may have led to the variation observed in the investment in the pair bond. Divergent mechanisms maintaining the pair bond and the ability to exploit a variety of food types, as well as other differences from previously-studied species of Callicebus suggests that this genus is more socially and behaviorally flexible than previously thought

Habitat preference in the yellow-tailed woolly monkey (lagothrix flavicauda) at Yambrasbamba, Peru

We assessed how habitat use and preference in the endemic, and Critically Endangered, yellow-tailed woolly monkey (Lagothrix flavicauda) are linked to forest structure and composition. The study took place in the community of Yambrasbamba in Northeastern Peru. Very little is known about the spatial distribution and habitat preference of L. flavicauda. Our objective is to identify and highlight the characteristics of habitats most utilized by L. flavicauda in order to contribute to its conservation by providing information that will be useful for the selection of priority sites for habitat protection, and to improve habitat quality. The study site was classified into three different use zones, high, medium, and low use, according to the number of presence records collected from May 2013 to February 2014 for one group of L. flavicauda. Forest structure and composition were assessed for all use classes using the Gentry vegetation transects methodology. Results show great variation in species composition across the three use zones. Food plants have, predominately, greater density, dominance and ecological importance in high use zones. Use zones presented similar forest structure, a reverse J-shape diameter distribution. None of the structural variables analyzed seem to be related to preference in L. flavicauda. (Published By University of Alabama Libraries

An island of wildlife in a human-dominated landscape: The last fragment of primary forest on the Osa Peninsula's Golfo Dulce coastline, Costa Rica.

Habitat loss and fragmentation, together with related edge effects, are the primary cause of global biodiversity decline. Despite a large amount of research quantifying and demonstrating the degree of these effects, particularly in top predators and their prey, most fragmented patches are lost before their conservation value is recognized. This study evaluates terrestrial vertebrates in Playa Sandalo, in the Osa Peninsula of Costa Rica, which represents the last patch of "primary" forest in the most developed part of this region. Our study indicates that the diversity of ground species detected within Playa Sandalo rival other areas under active conservation like Lapa Rios Ecolodge. Historical fragmentation, together with the maintenance of forest cover in isolated conditions, are potentially responsible for the species composition observed within Playa Sandalo; facilitating the development of a prey-predator system including ocelots, medium-size mammals, and birds at the top of the trophic chain. The high diversity of both habitat and vertebrates, its prime location and cultural value, as well as its unique marine importance represent the ideal conditions for conservation. Conservation of Playa Sandalo, and other small tropical forest remnants, might represent the only management option for wildlife conservation within ever growing human-dominated landscapes

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. © 2019, Springer Science+Business Media, LLC, part of Springer Nature