Saguinus Mystax Research Articles

Interspecific relations in a mixed-species troop of moustached tamarins, Saguinus mystax, and saddle-back tamarins, Saguinus fuscicollis (Platyrrhini:Callitrichidae), at the Río Blanco, Peruvian Amazonia.

This study examined the social interactions between moustached tamarins, Saguinus mystax, and saddle-back tamarins, Saguinus fuscicollis, living in a mixed-species troop at the Río Blanco, Peruvian Amazonia, between July 1985 and July 1986. Mixed-species troops were common among the S. mystax and S. fuscicollis populations in the Río Blanco study area; 72% of all sightings of S. mystax and 82% of all sightings of S. fuscicollis were in mixed-speices troops (study group excluded from analysis). In the study group, the two species spent on average 82% of time in association. Interactions were observed at a rate of one per 5 h of observation. Most interactions (96%) were agonistic. About 70% of agonistic interactions occurred at small food resources (crown diameter < 5 m and/or limited number of ripe fruits). Moustached tamarins were always dominant over saddle-back tamarins. Friendly interactions were extremely rare and were restricted to play invitations. Mutual calling was observed in the morning before the two species joined each other and during the day when they became separated. It is concluded that interspecific interactions and mutual calling incur some costs to the associated species but that these costs may be low.

The response of red-chested moustached tamarins to long calls from their natal and alien populations

Long calls of red-chested moustached tamarins, Saguinus l. labiatus, typically last 1–2 s and are made up of individual syllables. Their acoustic structure varies between populations. In this study, captive adult male and female tamarins of each of three different populations in Bolivia were played unfamiliar long calls from their natal and alien populations to determine whether they responded differentially to them. The results suggested that female tamarins respond selectively to male long calls from their natal populations.

Species and subspecies specificity in urine and scent marks of saddle-back tamarins (Saguinus fuscicollis)

Saguinus fuscicollisproduces scent marks which consist mainly of a mixture of urine and the secretions of circumgenital scent glands. The present study investigates the ability of saddle-back tamarins to discriminate between scent material from conspecifics and corresponding material from other species and to differentiate material from two subspecies of Saguinus fuscicollis.When choices between urine samples from conspecifics and from guinea pigs and choices between urine samples from conspecifics and from common marmosets were offered, the tamarins investigated samples from conspecifics more frequently. Similar responses were obtained when choices between scent marks from saddle-back tamarins and from common marmosets and between scent marks from saddle-back and red-chested moustached tamarins were offered. The tamarins also discriminated between scent marks and between extracts of scent marks from Saguinus f. fuscicollisand Saguinus f. illigeri.In these choice tests, subjects of both subspecies tended preferentially to investigate material from Saguinus f. fuscicollis.The results of these studies show that urine and scent marks contain chemical cues on which recognition of conspecifics can be based. Moreover, the scent marks of closely related subspecies also offer cues which could enable the tamarins to discriminate between them.

A Field observation of predation on a Moustached Tamarin(Saguinus mystax) by an Anaconda

A Field observation of predation on a Moustached Tamarin(Saguinus mystax) by an Anaconda

The Perception of Sex‐specificity in Long Calls of the Tamarin (Saguinus labiatus labiatus)

AbstractLong calls given by red‐chested moustached tamarins (Saguinus l. labiatus), typically 1–2 s in duration and made up of individual syllables, reveal distinctive sex‐specificity as well as population and individual differences in their acoustic structure. Distributions of male calls and female vocalizations are discrete with regard to two acoustic parameters, i.e. number of syllables and mean inter‐syllable intervals. Mean number of syllables produced in a given time is much greater in male than in female calls. I played back synthetic versions of the long calls varying in mean inter‐syllable intervals to captive tamarins and found that the sex differences were encoded in a relatively simple acoustic form. The tamarin is able to identify the sex of unfamiliar calling conspecifics by voice alone.

Locale‐specific Vocal Behaviour of the Tamarin (Saguinus I. labiatus)

AbstractA quantitative acoustic analysis of long calls of red‐chested moustached tamarins (Saguinus l. labiatus) was undertaken after capture in the primary forest of Northwestern Bolivia, comparing two populations. Two acoustic parameters are statistically significantly different. Acoustic properties distinguishing individual heterogeneity are quite consistent between the groups and completely different from cues separating population variability. As these two study groups were only 27 km apart when trapped, and as no geographical barriers prevented genetic exchanges between them, we assume populational vocal variability comparable to dialects in birds.

Body weights in mixed species troops of Saguinus mystax mystax and Saguinus fuscicollis nigrifrons in Amazonian Peru.

An investigation of body weights of members of mixed species troops of Saguinus mystax mystax and Saguinus fuscicollis nigrifrons was conducted at the Rio Blanco Research Station in northeastern Peru. A total of 107 adult and subadult tamarin monkeys were trapped, measured, and released. Data collected indicate that mean body weights for adult male and female moustached tamarins are 564 gm and 626 gm, respectively, whereas for adult saddle-back tamarins these values are 412 gm and 411 gm. Subadults weighed 11-27% less than adults. Body weights recorded in this study are significantly greater than those previously reported for tamarins of the same species and age living in other areas of Amazonian Peru. We hypothesize that, in the case of moustached and saddle-back tamarins, advantages associated with feeding and foraging in mixed species troops facilitate greater efficiency in resource monitoring and result in the maintenance of larger body weights.

Troop-specific responses to long calls of isolated tamarins (Saguinus mystax).

Recently captured moustached tamarins (Saguinus mystax) were briefly separated from other members of their troop. Most separated animals emitted long calls that were, in general, similar in acoustic structure to those of sympatric tamarin species while retaining species distinctiveness. Individual differences also appeared in call structure. The long calls of a separated animal were responded to almost entirely by members of the animal's own troop rather than by other troops, and reciprocal calling occurred among troop members significantly more often than expected by chance. Although there was no evidence of troop-specific call structure or dialect, there were troop-specific responses to the calls of separated tamarins. This response implies the existence of a stable and integrated troop structure that allows troop members to learn and to respond to the individual specific features of each troop member's calls.

Comparative studies on vertical separation, foraging behavior and traveling mode of saddle-backed tamarins (Saguinus fuscicollis) and red-chested moustached tamarins (Saguinus labiatus) in Northern Bolivia

The author made comparative studies on the ecology of saddle-backed tamarins (Saguinus fuscicollis) and red-chested moustached tamarins (S. labiatus) on the upper Amazon in northern Bolivia. The unit group of both species of monkeys was a family group composed of two to seven individuals, but they often formed polyspecific associations comprising one such family group each. However, both species preferred different layers of forest for foraging insects and traveling.S. fuscicollis mainly utilized the lower layer of the forest and foraged large-sized insects lurking in tree hollows, whereasS. labiatus mainly utilized the middle layer of the forest and foraged small-sized animals on branches. These differences were more clearly noticeable in secondary forest than in primary forest.

A Preliminary Field Study of the Moustached Tamarin Monkey (Saguinus mystax) in Northeastern Peru: Questions Concerned with the Evolution of a Communal Breeding System

A preliminary field study was conducted on moustached tamarin monkeys (Saguinus mystax) inhabiting Padre Isla, a small island in the Amazon Basin of northeastern Peru. Data presented indicate that groups are generally composed of 3-8 individuals including a single breeding female, 1-3 reproductively active males, nonreproductive adult females, and offspring. Migration of adults and subadults into and out of established groups is common, and it is unlikely that S. mystax social units represent nuclear or extended families. It is argued that rather than tending towards monogamy, the reproductive biology and mating activities of moustached tamarins are better understood in terms of a communal breeding system. In the case of this and perhaps other callitrichid species, such a system appears to involve female promiscuity and the participation of reproductively active adult male group members in caring for the young. The hypothesis that there is an important relationship between the number of adult male ‘helpers’ and infant survival is discussed.

Population recovery in the moustached tamarin (Saguinus mystax): Management strategies and mechanisms of recovery.

In 1978, 66% of the individuals of Saguinus mystax and 9.5% of Saguinus fuscicollis were cropped from a population at the Yarapa river, Peru. The effects of cropping on the remaining tamarin population were evaluated by conducting censuses in 1981 and 1982 and by trapping and release of Saguinus mystax in 1981. Three hundred kilometers of trail were covered in the censuses, and all the groups within the 1.9-km2 study area were located. Within three years after cropping, the population of S. mystax had increased by 124%, more than double the size left in 1978. Increased reproductive rate, early breeding, and reduced infant mortality contributed to the recovery. On the other hand, S. fuscicollis had decreased by 12% in the three years following the cropping but had increased in the fourth year to a level slightly below the precropping density. The cropping of more S. mystax than S. fuscicollis might have contributed to the decline of the latter. The cropping of a sizable percentage of S. mystax from a natural population does not seem to impair its recuperative powers. It may take longer than four years for a population exhibiting high density, such as that at the Yarapa site, to recover completely.

Coevolution: Heterotypic Schooling in Caribbean Reef Fishes

Coevolution: Heterotypic Schooling in Caribbean Reef Fishes