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 We collated published and unpublished data from 86 studies across 65 localities to assess titi monkey (Callicebinae) terrestriality.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

Sleeping above the enemy: sleeping site choice by black‐fronted titi monkeys (Callicebus nigrifrons)

The costs imposed by predation may result in behavioral adaptations to reduce mortality risk, including the choice and use of sleeping sites. The threat of predation, however, is rarely the sole force shaping sleeping site choice, which is likely to reflect other factors such as foraging needs as well. Here we describe the use of sleeping sites by three groups of small Neotropical monkeys, the black‐fronted titi monkeys (Callicebus nigrifrons), and evaluate the role of predation pressure and foraging optimization in their choice of sleeping sites. We monitored each group for 9–20 months at two Atlantic Forest sites in southeastern Brazil. The titi monkeys used taller and larger trees to sleep than the average trees at each study site and chose branches with high vegetation coverage and located in higher forest strata than those used during diurnal activity. Sleeping sites were randomly distributed within each group's home range, and the groups avoided using the same site on consecutive nights. The characteristics of the sleeping sites and the behavior of the titi monkeys suggest that predation avoidance, especially of scansorial carnivores, is an important factor driving sleeping site choice. We conclude that titi monkeys’ strategy to avoid predation while sleeping depends on the presence of a heterogeneous forest stratum with large emergent trees and liana tangles, which offer a physical barrier against predators.7910COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçãoSem informaçã

Behavioural thermoregulation in a small neotropical primate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)The maintenance of body temperature in endothermic animals imposes considerable metabolic costs that vary with air temperature fluctuations. To minimise these costs, endotherms can adopt certain behaviours to adjust the pattern of heat transfer between their bodies and the environment. In this study, we evaluated whether a small Neotropical primate, the black-fronted titi monkey (Callicebus nigrifrons), living in a seasonal environment can use behavioural mechanisms to cope with fluctuations in the air temperature. We monitored the air temperature and the titi monkeys' behaviour over 1yr. When the animals were inactive, we recorded the microhabitat used, the huddling between individuals and the body postures adopted. The monkeys primarily responded to air temperature fluctuations through microhabitat selection: they spent more time in sunny places and used higher strata of forest under lower temperatures. Moreover, they used sunny microhabitats during the first hour of their active period after colder nights. The monkeys did not huddle or change body postures in response to air temperature fluctuations. Huddling behaviour seemed to be primarily influenced by social interactions, and body postures were more energy conserving, regardless of temperature. Titi monkeys, however, used more energy-conserving postures and huddling behaviour under cloudy conditions than sunny conditions, suggesting that these behaviours may be important when they are unable to thermoregulate by microhabitat selection. We concluded that fluctuations in air temperature can promote significant changes in the behaviour of titi monkeys and can impose important restrictions on mammals' activities, even in tropical regions.The maintenance of body temperature in endothermic animals imposes considerable metabolic costs that vary with air temperature fluctuations. To minimise these costs, endotherms can adopt certain behaviours to adjust the pattern of heat transfer between th1204331339FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)sem informaçãosem informaçãoWe would like to thank the Municipal Secretariat of Planning and Environment of Jundiaí for granting permission to conduct this research at Serra do Japi Municipal Reserve. We also thank J. C. Bicca-Marques, P. S. Oliveira, C. S. Martins and M. B.Nagy-Re

From dropping to dropping: the contribution of a small primate to seed dispersal in Atlantic forest

The dynamic interaction between animals and plants through frugivory and seed dispersal is one of several ecological processes that modulates tropical biodiversity. Here we evaluated the potential role of a highly-frugivorous Neotropical primate, the black-fronted titi monkey (Callicebus nigrifrons), as seed disperser. We studied two titi monkey groups in semideciduous Atlantic Forest remnants. Each group fed on over 49 zoochorous plant species in about one year and ingested seeds from nearly a half of them, especially those with small seeds (< 0.5 cm). The groups of titi monkeys defecated a large number of seeds, reaching over 300 seeds per day (1-305). More than half of the total deposited seeds and seed species germinated after gut passage, however gut passage reduced germination success in three of five evaluated species. Feces were deposited in small clumps distributed across groups' home range. We suggest that the observed distribution pattern of feces may enhance plant reproductive fitness by increasing the probability of seeds being deposited far from parent plants, in novel and favorable sites. We concluded that the seed handling and deposition behavior of black-fronted titi monkey make this primate an important agent for Atlantic forest regeneration100CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorFAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulosem informação2008/05127-0; 2010/04034-9; 2009/12124-

Playback Responses Of Socially Monogamous Black-fronted Titi Monkeys To Simulated Solitary And Paired Intruders

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Many birds and primates use loud vocalizations to mediate agonistic interactions with conspecifics, either as solos by males or females, or as coordinated duets. The extensive variation in duet complexity, the contribution of each sex, and the context in which duets are produced suggest that duets may serve several functions, including territory and mate defense. Titi monkeys (Callicebus spp.) are believed to defend their home range via solo loud calls or coordinated duets. Yet there are remarkably few experimental studies assessing the function of these calls. Observations of interactions between wild established groups and solitary individuals are rare and, therefore, controlled experiments are required to simulate such situations and evaluate the mate and joint territorial defense hypotheses. We conducted playback experiments with three free-ranging groups of habituated black-fronted titi monkeys (Callicebus nigrifrons) to test these hypotheses. We found that titi monkeys responded to the three conspecific playback treatments (duets, female solos, and male solos) and did not respond to the heterospecific control treatment. The monkeys did not show sex-specific responses to solos (N = 12 trials). Partners started to duet together in 79% of their responses to playback-simulated rivals (N = 14 calls in response to playback). Males started to approach the loudspeaker before females regardless of the type of stimulus. The strength of the response of mated pairs to all three conspecific treatments was similar. Overall, our results are consistent with the idea that black-fronted titi monkeys use their loud calls in intergroup communication as a mechanism of joint territorial defense. (C) 2015 Wiley Periodicals, Inc.771111351142Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Natural Sciences and Engineering Research Council of Canada (NSERC)Canada Foundation for InnovationUniversity of WinsorConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Government of OntarioFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2008/05127-0]CAPES [BEX 5637/11-2]CNPq [303154/2009-8, 303306/2013-0

Should I store, or should I sync? : the breeding strategy of two small Neotropical primates under predictable resource availability

Primates employ many strategies to deal with the costs of reproduction. While income breeders exploit the food available in their environment during lactation, the most costly phase of reproduction, capital breeders tend to store energy for use in the period. We analyzed the relationship between resource availability and lactation in Callicebus coimbrai (n=2 groups) and Callicebus nigrifrons (n=2 groups) in four Brazilian Atlantic forest remnants, to assess their breeding strategy. We recorded the occurrence of births and breastfeeding events to assess birth seasonality and lactation period and length while monitoring monthly fruit availability. We recorded 11 births (five for C. coimbrai, and six for C. nigrifrons), all restricted to the end of the lean season and the beginning of the rich season. Lactation coincided with periods of increased fruit availability. We suggest that the breeding pattern of Callicebus coimbrai and C. nigrifrons is compatible with an income-based breeding strategy602113118CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorDAAD - Deutscher Akademischer AustauschdienstFAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulonão temnão tem2010/04034-9; 2008/05127-0; 2009/12124-

Estimating primate population densities: the systematic use of playbacks along transects in population surveys

Accurate measures of animal population densities are essential to assess their status, demography, and answer ecological questions. Among several methods proposed to collect abundance data, line transect sampling is used the most. The assumptions required79219FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS - FAPEMIG2012/14245-2sem informaçãoWe thank the Municipal Secretariat of Planning and Environment of Jundiaí, the administration of the Colinas do Atibaia condominium, and C. Knogge for the permission to conduct playback trials at Serra do Japi Municipal Reserve, Ribeirão Cachoeira fores

Playback responses of socially monogamous black-fronted titi monkeys to simulated solitary and paired intruders

Many birds and primates use loud vocalizations to mediate agonistic interactions with conspecifics, either as solos by males or females, or as coordinated duets. The extensive variation in duet complexity, the contribution of each sex, and the context in which duets are produced suggest that duets may serve several functions, including territory and mate defense. Titi monkeys (Callicebus spp.) are believed to defend their home range via solo loud calls or coordinated duets. Yet there are remarkably few experimental studies assessing the function of these calls. Observations of interactions between wild established groups and solitary individuals are rare and, therefore, controlled experiments are required to simulate such situations and evaluate the mate and joint territorial defense hypotheses. We conducted playback experiments with three free-ranging groups of habituated black-fronted titi monkeys (Callicebus nigrifrons) to test these hypotheses. We found that titi monkeys responded to the three conspecific playback treatments (duets, female solos, and male solos) and did not respond to the heterospecific control treatment. The monkeys did not show sex-specific responses to solos (N=12 trials). Partners started to duet together in 79% of their responses to playback-simulated rivals (N=14 calls in response to playback). Males started to approach the loudspeaker before females regardless of the type of stimulus. The strength of the response of mated pairs to all three conspecific treatments was similar. Overall, our results are consistent with the idea that black-fronted titi monkeys use their loud calls in intergroup communication as a mechanism of joint territorial defense. © 2015 Wiley Periodicals, Inc

The Role of Grunt Calls in the Social Dominance Hierarchy of the White-Lipped Peccary (Mammalia, Tayassuidae)

<div><p>Grunt-like calls are present in the vocal repertoire of many group-living mammals and seem to facilitate social interactions between lower and higher-ranking members. The white-lipped peccary (<i>Tayassu pecari</i>) lives in stable hierarchical mixed-sex groups and like non-human primates, usually emits grunt-like calls following aggressive interactions, mainly during feeding contexts. We investigated the possible functions of peccaries’ grunt-like calls and their relationship to the individuals’ social rank, identity, and sexual dimorphism. We observed that low-ranking individuals emitted grunt-like calls more often than high-ranking ones, and that the alpha male never emitted this vocalization. Moreover, the mean minimum frequency of grunt-like calls decreased as the peccary’s rank increased. The findings revealed differences among individual grunts, but the low accuracy of cross-validation (16%) suggests that individual recognition in peccaries may be less important than an honest signal of individual social status. In addition, the absence of differences in the acoustic parameters of grunt-like calls between males and females points to the lack of sexual dimorphism in this species. We verified that after hearing grunt calls, dominant opponents were more likely to cease attacking a victim, or at least delay the continuation of conflict, probably decreasing the severity of agonistic interactions. Our findings are particularly important to improve the current understanding of the role of grunt-like calls in herd-living mammals with linear dominant hierarchies, and strongly suggest that they are involved in the maintenance of herd social stability and cohesion.</p></div

Mean values (± standard deviation) of the acoustic parameters for grunts emitted by white-lipped peccaries according to the ranking position.

<p>Lower numbers correspond to higher positions in the dominance hierarchy. All measurements were taken from 50 samples from each individual. The percentage of correct cross-classified grunt calls for each individual based on the conventional (DFA) and permuted discriminant analysis (pDFA) is also presented, based on 37 calls for each individual.</p