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 We collated published and unpublished data from 86 studies across 65 localities to assess titi monkey (Callicebinae) terrestriality.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

Stopover 1 50% MCP Core Foraging Area.

<p>Daytime foraging area used by the Orinoco Geese at Stopover 1, December 2 to December 16. Inset map shows the foraging location with respect to the typical night-time roost about 10 km away and 95% Minimum Convex Polygon (MCP) of daytime and night-time locations. The underlying yellow polygon is the 50% MCP core area of use. Google Earth accessed 11 April 2012 coordinates 13°28′31.23′′S; 66°49′28.44′′W.</p

Major Movements by Date, Time and Phase of the Moon.

<p>Major Movements (>5 km per period) by Julian date, time, and phase of the moon between October 27 and December 31, 2010. For each day, shaded areas are times when the moon is not visible in the sky at the goose's location. Movements are diagrammed by date and time with red diamonds sized in relation to the log of the distance traveled (in km) during that period. Each movement is placed at the midpoint of the time period during which the goose traveled, which is typically within a 6 h period between 6 pm and midnight or midnight and 6 am. Vertical red lines on the furthest left points and one anomalous point at 07∶00 demonstrate these potential spreads in timing.</p

Orinoco Goose Migration Route.

<p>The complete migration (pink line) of the Orinoco Geese caught in Manú National Park, October 27, 2010. Locations denote date and local time for points discussed in the text. Google Earth accessed 19 April 2012 coordinates 13°14′33.19′′S; 68°35′31.77′′W.</p

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