Wild Blonde Capuchins (Sapajus flavius) Perform Anointing Behaviour Using Toxic Secretions of a Millipede (Spirobolida: Rhinocricidae).

Defensive secretions of millipedes are remarkable for containing toxic quinones known to efficiently repell hematophagous arthropods. Here we show that Endangered blonde capuchin monkeys make use of such secretions. We (i) describe the anointing behavior performed by the monkeys (ii) identify the millipede species used in the process (iii) describe the volatile chemical composition of its secretion. The blonde capuchin monkeys selectively searched for millipedes hidden under the ground. We observed three bouts of anointing behavior, performed by 13 individuals of all age classes (from adults to independent infants), both solitarily (1 event) and socially (10 events). The only millipede species used by the monkeys is an undescribed species of the genus Poecilocricus (Spirobolida, Rhinocricidae). The volatile chemical composition of the secretions was predominantly comprised of a mixture of benzoquinones and hydroquinones. The social nature of the behavior and time of the observations (mosquito season), suggest that social bonding and mosquito avoidance is linked to the anointing behavior of the monkeys.

Small but wise: Common marmosets (Callithrix jacchus) use acoustic signals as cues to avoid interactions with blonde capuchin monkeys (Sapajus flavius).

Vocalizations are often used by animals to communicate and mediate social interactions. Animals may benefit from eavesdropping on calls from other species to avoid predation and thus increase their chances of survival. Here we use both observational and experimental evidence to investigate eavesdropping and how acoustic signals may mediate interactions between two sympatric and endemic primate species (common marmosets and blonde capuchin monkeys) in a fragment of Atlantic Rainforest in Northeastern Brazil. We observed 22 natural vocal encounters between the study species, but no evident visual or physical contact over the study period. These two species seem to use the same area throughout the day, but at different times. We broadcasted alarm and long distance calls to and from both species as well as two control stimuli (i.e., forest background noise and a loud call from an Amazonian primate) in our playback experiments. Common marmosets showed anti-predator behavior (i.e., vigilance and flight) when exposed to blonde capuchin calls both naturally and experimentally. However, blonde capuchin monkeys showed no anti-predator behavior in response to common marmoset calls. Blonde capuchins uttered long distance calls and looked in the direction of the speaker following exposure to their own long distance call, whereas they fled when exposed to their own alarm calls. Both blonde capuchin monkeys and common marmosets showed fear behaviors in response to the loud call from a primate species unknown to them, and showed no apparent response to the forest background noise. Common marmoset responses to blonde capuchin calls suggests that the latter is a potential predator. Furthermore, common marmosets appear to be eavesdropping on calls from blonde capuchin monkeys to avoid potentially costly encounters with them.

Vocal Repertoire of Wild Blonde Capuchins (Sapajus flavius) and Contextual Use of Calls.

Despite advances in the study of capuchin monkeys (Cebus and Sapajus), there is fairly limited information on their vocal communication systems. The present study focused on investigating the structure and use of vocalizations by wild blonde capuchin monkeys, Sapajus flavius. The study subjects produced 29 different call types, which we grouped into 10 categories according to their behavioral context. The number of call types per context varied from one to six. Some of the call types in the vocal repertoire were only produced by individuals of specific age classes. The "nhan" call, for instance, was only emitted by infants, whereas the "ghrr" call was specific to adults. Other call types had no age-specificity and were produced by animals of two or more age categories. Discriminant Function Analysis correctly classified 77.4% of calls to type (n = 14 types). The "huh" and "huh-1var" calls, which are food-associated calls, were most commonly used, together representing approximately 52% of recorded vocalizations. Information on the vocal repertoire of blonde capuchins increases our knowledge of this very little known and Critically Endangered species. Ultimately, it may be used as a tool to help survey these animals in the wild and to assess welfare in captivity.

Critically endangered blonde capuchins fish for termites and use new techniques to accomplish the task.

We report the spontaneous modification and use of sticks to fish for termites, above the ground, in wild blonde capuchins (Cebus flavius). These critically endangered Neotropical primates inhabit remnants of the Atlantic Forest. They used two previously undescribed techniques to enhance their termite capture success: nest tapping and stick rotation. The current ecologically based explanation for tool use in wild capuchins (i.e. terrestrial habits and bipedalism) must be viewed cautiously. Instead, remarkable manual skills linked to a varied diet seem important in promoting tool use in different contexts. The repertoire of tool-using techniques employed by wild capuchins has been expanded, highlighting the behavioural versatility in this genus.