Activity budget and social behavior of urban capuchin monkeys, Sapajus sp. (Primates: Cebidae)

Constant changes in natural environments impose challenges to wild animal populations, especially those that depend on social life. We gathered data on the activity budget and social interactions of a capuchin monkey (Sapajus sp.) group of 17 individuals confined to an urban green area receiving human food supplementation. We observed the capuchins between 7:00 am and 5:00 pm, three days a month, between January 2012 and June 2013 (total of 530 hours of direct observations). We collected 15,208 behavioral records through instantaneous scan sampling and 2,538 events of social interaction in an adapted version of the “all occurrences” method. Activity budget of capuchins was dominated by traveling (42%) and foraging (38%), followed by feeding (10%), social interactions (5%), resting (4%), and others (2%). Except for feeding, the time spent on other activities varied across sex-age classes. Social interactions of capuchins were dominated by affiliative interactions (80%), mainly social play, followed by agonistic (11%) and cooperative (10%) interactions. Sexual interactions were rare (0.4%) and often involved juveniles (45% of the events). Juveniles performed most of the social interactions, followed by the alpha male, and were the main receptors of grooming, food sharing, and agonism. On the other hand, they were the main group involved in allocarrying of infants. Grooming between females and from them to alpha male was infrequent. However, grooming of the alpha male towards the adult females was frequent. We interpreted the deviations in the activity budget and social interactions of the urban capuchins as effects of human food supplementation and restriction on dispersal, illustrating the behavioral ability of capuchin monkeys to adjust their activity in human-altered environments.(AU)

Activity budget and social behavior of urban capuchin monkeys, Sapajus sp. (Primates: Cebidae)

Constant changes in natural environments impose challenges to wild animal populations, especially those that depend on social life. We gathered data on the activity budget and social interactions of a capuchin monkey (Sapajus sp.) group of 17 individuals confined to an urban green area receiving human food supplementation. We observed the capuchins between 7:00 am and 5:00 pm, three days a month, between January 2012 and June 2013 (total of 530 hours of direct observations). We collected 15,208 behavioral records through instantaneous scan sampling and 2,538 events of social interaction in an adapted version of the “all occurrences” method. Activity budget of capuchins was dominated by traveling (42%) and foraging (38%), followed by feeding (10%), social interactions (5%), resting (4%), and others (2%). Except for feeding, the time spent on other activities varied across sex-age classes. Social interactions of capuchins were dominated by affiliative interactions (80%), mainly social play, followed by agonistic (11%) and cooperative (10%) interactions. Sexual interactions were rare (0.4%) and often involved juveniles (45% of the events). Juveniles performed most of the social interactions, followed by the alpha male, and were the main receptors of grooming, food sharing, and agonism. On the other hand, they were the main group involved in allocarrying of infants. Grooming between females and from them to alpha male was infrequent. However, grooming of the alpha male towards the adult females was frequent. We interpreted the deviations in the activity budget and social interactions of the urban capuchins as effects of human food supplementation and restriction on dispersal, illustrating the behavioral ability of capuchin monkeys to adjust their activity in human-altered environments.

The win-stay rule in foraging decisions by free-ranging titi monkeys (Callicebus cupreus cupreus) and Tamarins (Saguinus imperator imperator and Saguinus fuscicollis weddelli).

Rainforest primates need to apply distinct foraging rules for efficiently using the spatial knowledge of the distribution of resources showing different temporal patterns of renewal. A win-stay rule is very important for exploiting abundant, long-lasting resources. Here, the author tests the use of this rule in wild groups of emperor tamarins (Saguinus imperator imperator), saddle-back tamarins (Saguinus fuscicollis weddelli), and titi monkeys (Callicebus cupreus cupreus) during a series of foraging tasks. Four feeding stations composed of 8 visually similar feeding platforms (2 containing a food reward and 6 containing a sham reward) were constructed. The location of food rewards was reliable during some experiments and unreliable during others. All 3 species consistently adopted a win-stay rule for returning to reward platforms when their location was predictable over time but stopped using it when their spatial distribution changed randomly across experimental trials.

Abundance, use of space, and activity patterns of white-faced sakis (Pithecia pithecia) in French Guiana.

White-faced sakis (Pithecia pithecia) are among the least studied neotropical primates. The combination of shy and quiet behavior, their ability to move silently, and the extreme difficulty of capturing them may explain why very few field studies have been undertaken in undisturbed habitats. During the course of a wildlife rescue in French Guiana, six individuals were captured and translocated to a safe area of primary rainforest. In this area, based on the observation of 35 groups, the average group size was 2.3 animals (SD = 1.2) and a density of 0.28 group/km(2) (0.64 individuals/km(2)) was estimated from transect censuses. Our study focused successively on three radio-collared animals (two males and one female) over a 287-day period, starting from release to the loss of the animal. From the study start, the triangulation method was used prior to habitutation to human presence, followed thereafter by 1,327 hr of visual monitoring. The translocated animals settled down, and two of them had a stable and compact home range. Two of them merged in association with members of the resident population. A resident group had a much larger home range than previously reported: 148 and 287 ha, using grid cells and 100% minimum convex polygon techniques, respectively. A group composed of two translocated individuals (one male and one female) had a home range of 68 and 135 ha using the same techniques. Additionally, two solitary animals used 152 and 162 1-ha quadrats. We observed animals (translocated and residents) moving quickly in one direction up to 11.5 km. The mean daily path length of resident animals was 1,880 m. Sakis used the lower strata of the forest more when in group, and the intermediate strata more when solitary. Allogrooming is fairly common in social groups. On average, the activity period ranged from 7:17 to 15:59 hr.

Locomotor behavior of Lagothrix lagothricha and Ateles belzebuth in Yasuní National Park, Ecuador: general patterns and nonsuspensory modes.

Field study of the locomotor behavior of sympatric woolly monkeys (Lagothrix lagothricha) and spider monkeys (Ateles belzebuth) in undisturbed rainforest of northern Ecuador revealed similar patterns in use of plant forms (categorized tree and liana structure), and substantial differences in the frequencies of use of different grouped modes (aggregates of kinematically similar specific modes). Lagothrix progressed more than Ateles by leaping/dropping and quadrupedal walking/running, whereas Ateles exhibited more suspensory locomotion. Grouped modes are associated with different plant forms in similar ways in the two species. In contrast, the species differed in use of tree zone (trunk/bole, major branches, intermediate branches, and terminal branches), with Lagothrix using intermediate branches and Ateles terminal branches more. Correlated with this difference was greater use by Lagothrix of quadrupedal movement, especially on intermediate branches, and greater use of suspensory modes by Ateles, especially in the terminal zone. Further research is needed to determine how these patterns are facilitated and constrained by morphological mechanisms. Analysis of specific locomotor modes within groups shows several interspecific differences in relative frequencies.

Ranging behavior and intraspecific relationships of masked titi monkeys (Callicebus personatus personatus).

Two neighboring groups of masked titi monkeys (Callicebus personatus personatus) were observed for nearly 240 hr over a 5-mo period. Minimum home range estimates for the groups were 10.7 and 12.3 ha; daily path length averaged 1 km. Each group shared a minimum of nearly 20% of its range with neighbors, and encounters between groups were rare and exclusively vocal. There was no strong evidence that titis called at the edge of their ranges or used non-overlap areas more intensively. Masked titis at this site were therefore not markedly territorial, in contrast to other descriptions of this genus. However, this study was carried out at a time of unusually low rainfall, which may have influenced behavior. Further longer-term studies of adjacent groups are therefore required to assess environmental, specific, and subspecific factors affecting territoriality in this genus.

Fur rubbing behavior in free-ranging black-handed spider monkeys (Ateles geoffroyi) in Panama.

Members of the population of black-handed spider monkeys (Ateles geoffroyi) on Barro Colorado Island, Panama, use the leaves of three Rutaceae species in a behavior that resembles fur rubbing in the white faced capuchin (Cebus capucinus). This behavior has not been reported from other sites where Ateles has been studied. During more than 1,200 hours of observation, 30 episodes of this behavior were recorded ad libitum. Adult males engage in this behavior more than adult females. Season did not impact the frequency of the behavior. The behavior described here differs in many respects from that reported for Cebus capucinus, and does not fit the hypotheses that the behavior functions in repelling insects or other antiseptic purposes. It is proposed that fur rubbing in this group of spider monkeys is a modification of a behavior previously recorded in Ateles and may function in scent marking.

Estudio de las conductas agonísticas y afiliativas de un grupo de monos araña (Ateles geoffroyi) en cautiverio / Study of agonistic and affiliative behaviors in a grup of captive (Ateles geoffroyi) monkys

En cualquier especie, los patrones agonísticos y afiliativos son considerados, junto con la sexualidad y el juego, como los más representativos del funcionamiento correcto de un grupo. De hecho, son manifestaciones de las fuerzas cooperativas y competitivas que fundamentan su organización social. Son muchos los autores que han adoptado el término ®agonístico¼, para referirse a cualquier actividad que incluya agresión, conciliación y retirada. Por otro lado, las pautas afiliativas son extremadamente diversas o incluyen todas las conductas amistosas que promueven la cohesión entre individuos. Con respecto al mono araña silvestre (Ateles geoffroyi), se ha visto que probablemente debido a su temperamento irascible y a las condiciones específicas de su hábitat, presentan relaciones de dominancia difusas y su patrón de conductas afiliativas no parece ser muy extenso ni en tiempo ni en frecuencia. Para el presente estudio se trabajó con un grupo de nueve monos araña cautivos, monitoreando sus conductas cooperativas y competitivas. Las muestras fueron obtenidas videofilmando individuos focales. Se encontraron diferencias significativas en los patrones competitivos y cooperativos tanto en las relaciones intragrupales como en los dos periodos muestreados (1996 y 1992)

Diet and feeding ecology of Ateles belzebuth belzebuth at Maracá Ecological Station, Roraima, Brazil.

The diet and feeding behaviour of habituated group of free-ranging spider monkeys (Ateles belzebuth belzebuth) were studied from 1987 to 1989. Their dietary patterns were analysed in relation to the temporal and spatial distribution of food resources. The results indicate that ripe fruit was regularly eaten throughout the study period and that diet composition was significantly related to the overall availability of ripe fruit sources.

Desenvolvimento comportamental do Muriqui (Brachyteles arachnoides) na Estaçäo Ecológica de Caratinga, Minas Gerais / Behavioral development of the young muriqui (Brachyteles arachnoides) at the Biological Station of Caratinga, Minas Gerais

Filhotes primatas nascem relativamente desprotegidos, necessitando de cuidados de um indivíduo adulto para garantir sua sobrevivência até estarem aptos a manterem-se sozinhos. As mäes representam o seu primeiro e mais intenso vínculo social. Porém, com o passar do tempo, os filhotes väo se afastando dela, aprendendo a manterem-se sozinhos. Durante o desenvolvimento, as habilidades motoras e sociais se alteram, capacitando-os a desenvolver atividades cada vez mais complexas. Esta auto-suficiência altera a interaçäo mäe-filhote quanto ao interesse pela manutençäo do relacionamento. A presente pesquisa teve como objetivo estudar o processo de independência do filhote muriqui(Brachyteles arachnoides), espécie de primata do Novo Mundo endêmica da Mata Atlântica. Foram observados 29 díades mäe-filhote durante os três primeiros anos de vida dos infantes, nos períodos de agosto/1989 a março/1990 e junho/1994 a junho/1995. As observaçöes foram coletadas através do método de amostragem animal-focal e Ad libitum. Obteve-se 2732 focais resultando em 24900 minutos de observaçäo. Constatou-se uma diminuiçäo gradual do contato mäe-filhote, sendo que apenas no final do primeiro ano de vida, os infantes permaneceram 50 por cento do tempo fora de contato. Por outro lado, o contato esteve diretamente relacionado com a atividade materna, diminuindo mais rapidamente nos episódios de alimentaçäo do que nos de deslocamento e descanso materno. O leite foi o principal alimento dos filhotes até o sexto mês de vida, sendo as folhas o alimento de desmame mais importante após esta idade. A manipulaçäo de objetos pelos filhotes esteve bastante vinculada ao ítem utilizado pelas mäes durante sua alimentaçäo. Os filhotes mostraram índices de sociabilidade superior aos adultos, principalmente em brincadeiras sociais. Foram observadas interaçöes entre os filhotes e os animais adultos e subadultos, tendo sido os filhotes machos mais requisitados. O desenvolvimento dos filhotes muriquis assemelhou-se bastante ao do macaco-aranha e ao dos grandes símios

Autonomic balance in Saimiri sciureus and Callicebus moloch: relation to life-style.

Previous research has shown heart rate to be substantially higher in squirrel monkeys (Saimiri sciureus) than titi monkeys (Callicebus moloch). In order to evaluate whether species differences in heart rate can be accounted for by contrasting patterns of autonomic activity, heart rate in response to novel test conditions was compared using standard pharmacological agents that selectively block the sympathetic (propranolol) or parasympathetic (atropine) components of the autonomic nervous system. Squirrel monkeys were found to exhibit greater sympathetic response to novelty than titi monkeys. In contrast, sympathetic activity in titi monkeys, but not squirrel monkeys, was quickly counteracted by a strong parasympathetic response. Intrinsic heart rates, estimated by blocking both parasympathetic and sympathetic input to the heart, were within the ranges of values predicted by body weight. Heart rate for titi monkeys stabilizes at intrinsic heart rate, whereas heart rate for squirrel monkeys is maintained well above intrinsic heart rate in a novel environment. The contrast between species in autonomic balance is consistent with and probably contributes to each species characteristic mode of interacting with their social and non-social environment.

Foraging and ranging patterns in white-bellied spider monkeys.

Ranging and foraging patterns observed during a field study of the behavioral ecology of Ateles belzebuth belzebuth are analysed in the context of temporal and spatial variation in the distribution of plant resources at the study site. The study group exhibited two basic patterns of foraging behaviour and habitat exploitation, which appeared to correlate with the observed variation in resource availability. During the dry season, when the relative abundance of fruit decreased, the spider monkeys ranged over a smaller area, repeatedly visiting a few intensively used fruiting and sleeping trees. As fruit abundance increased during the course of the wet season, the study group expanded its range, and both the daily path length and the number of fruiting trees visited increased daily. These patterns are analysed and evaluated in relation to foraging strategies.

Vertebrate predation in Cebus capucinus: meat eating in a neotropical monkey.

A long-term study of two groups of white-faced capuchins (Cebus capucinus) in Santa Rosa National Park in Costa Rica provides evidence of unusually high levels of vertebrate predation compared to those reported in other field studies of Cebus. The hunting techniques for different prey types are described, and several questions concerning vertebrate predation in primates are addressed. Why is there variation between individuals and between groups in the rate of predation? Why do males hunt more than females? Previous hypotheses to explain hunting in Old World primates are applied to this Neotropical example. Finally, I argue that successful vertebrate predation can readily arise in species like Cebus, which are characterized by opportunistic foraging patterns, manipulative and cognitive skills and well-developed techniques for locating and subduing invertebrate prey.