Habitat preference in the critically endangered yellow-tailed woolly monkey (Lagothrix flavicauda) at La Esperanza, Peru.

Habitat loss is one of the main threats to wildlife. Therefore, knowledge of habitat use and preference is essential for the design of conservation strategies and identification of priority sites for the protection of endangered species. The yellow-tailed woolly monkey (Lagothrix flavicauda Humboldt, 1812), categorized as Critically Endangered on the IUCN Red List, is endemic to montane forests in northern Peru where its habitat is greatly threatened. We assessed how habitat use and preference in L. flavicauda are linked to forest structure and composition. The study took place near La Esperanza, in the Amazonas region, Peru. Our objective was to identify characteristics of habitat most utilized by L. flavicauda to provide information that will be useful for the selection of priority sites for conservation measures. Using presence records collected from May 2013 to February 2014 for one group of L. flavicauda, we classified the study site into three different use zones: low-use, medium-use, and high-use. We assessed forest structure and composition for all use zones using 0.1 ha Gentry vegetation transects. Results show high levels of variation in plant species composition across the three use zones. Plants used as food resources had considerably greater density, dominance, and ecological importance in high-use zones. High-use zones presented similar structure to medium- and low-use zones; thus it remains difficult to assess the influence of forest structure on habitat preference. We recommend focusing conservation efforts on areas with a similar floristic composition to the high-use zones recorded in this study and suggest utilizing key alimentation species for reforestation efforts.

Geographic comparison of plant genera used in frugivory among the pitheciids Cacajao, Callicebus, Chiropotes, and Pithecia.

Pitheciids are known for their frugivorous diets, but there has been no broad-scale comparison of fruit genera used by these primates that range across five geographic regions in South America. We compiled 31 fruit lists from data collected from 18 species (three Cacajao, six Callicebus, five Chiropotes, and four Pithecia) at 26 study sites in six countries. Together, these lists contained 455 plant genera from 96 families. We predicted that 1) closely related Chiropotes and Cacajao would demonstrate the greatest similarity in fruit lists; 2) pitheciids living in closer geographic proximity would have greater similarities in fruit lists; and 3) fruit genus richness would be lower in lists from forest fragments than continuous forests. Fruit genus richness was greatest for the composite Chiropotes list, even though Pithecia had the greatest overall sampling effort. We also found that the Callicebus composite fruit list had lower similarity scores in comparison with the composite food lists of the other three genera (both within and between geographic areas). Chiropotes and Pithecia showed strongest similarities in fruit lists, followed by sister taxa Chiropotes and Cacajao. Overall, pitheciids in closer proximity had more similarities in their fruit list, and this pattern was evident in the fruit lists for both Callicebus and Chiropotes. There was no difference in the number of fruit genera used by pitheciids in habitat fragments and continuous forest. Our findings demonstrate that pitheciids use a variety of fruit genera, but phylogenetic and geographic patterns in fruit use are not consistent across all pitheciid genera. This study represents the most extensive examination of pitheciid fruit consumption to date, but future research is needed to investigate the extent to which the trends in fruit genus richness noted here are attributable to habitat differences among study sites, differences in feeding ecology, or a combination of both.

Insect prey foraging strategies in Callicebus oenanthe in northern Peru.

Titi monkeys (genus Callicebus) are small-bodied platyrrhines that supplement their predominantly frugivorous diet with variable amounts of leaves, seeds, and/or arthropod prey. Notable interspecific variation in the amount of insect prey in the diet has been observed in Callicebus, ranging from 0% to 20%. In this study, I investigate the degree and type of prey foraging in a little-known species, Callicebus oenanthe inhabiting a fragmented, secondary forest on the foothills of the Andes in northern Peru. I present data on prey type, prey search and capture techniques, substrate/vegetation use, foraging height, prey capture efficiency, and seasonal variation of insect prey foraging in one group of C. oenanthe observed from January to August 2005. Insect prey accounted for 22% of the diet, the highest amount reported for any Callicebus species to date, and insects from at least six different orders were included. C. oenanthe was mainly an investigative forager of hidden prey, manipulating easy-to-open substrates such as rolled up leaves, and hunted ant swarms and larger insects opportunistically. Insect foraging was predominant during the dry season (26%) and decreased during the wet season (13%). The study group foraged mostly in the understory (2-6 m) within vine-laden shrubs and trees, which may conform to an anti-predator strategy of crypticity. Overall the group had an 83% insect capture success rate. These data suggest that insect prey is an important part of the diet of C. oenanthe and may be especially notable during periods of resource scarcity. This study adds to the knowledge concerning insect prey foraging in Callicebus, which can have an important role in defining ecological strategies in the selection of secondary protein food resources within a given ecosystem.

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.

Observations of a daytime birthing event in wild titi monkeys (Callicebus oenanthe): implications of the male parental role.

Behaviors displayed during birth events, including prenatal, parturition, and postpartum periods, can give insight into caretaking roles in species in which the offspring is cared for by individuals other than the mother. Titi monkeys, genus Callicebus, exhibit a pair-bonded social system along with intense male care of offspring. Here, I report the first case of a birth seen in the wild in a group of Callicebus oenanthe, a little-known species in northern Peru, and describe infant care and development during the first few months after birth. Detailed behavior during the birth sequence as well as ad libitum data postpartum were recorded on nursing and infant care behaviors, including infant carrying, infant grooming, anogenital cleaning, protection, playing, and food sharing. In the 3 h preceding and during parturition, the male remained in contact with or in close proximity to the female (<1 m). The male licked and examined the newborn 3 min after parturition, carried the infant within 24 h after birth, was the main carrier of the infant, and was the predominant manual groomer of the infant during the first 4 months after birth. I argue that the male plays an integral role during the birth in order to establish his bond with the infant as well as reinforce infant care duties to the female and in predator vigilance. In light of various explanations for the exhibition of intense paternal care, I suggest that the male titi monkey provides infant care to release the female of these duties in order that she may spend more time foraging, thus potentially increasing the pair's overall reproductive output.