Saguinus Mystax Research Articles

Seed swallowing in Tamarins : Evidence of a curative function or enhanced foraging efficiency ?

Nonhuman primates represent a major component of the frugivore biomass in several rain-forest communities. Although there is considerable evidence that prosimians, monkeys, and apes serve as dispersal agents for many tropical trees, little attention has been paid to the more basic questions of why certain species of primates swallow and void seeds, and what, if any, are the advantages to an animal of having a large, hard, bolus pass through its digestive tract. We examine patterns of fruit-eating and seed-swallowing in two species of free-ranging tamarins: Saguinus mystax and Saguinus geoffroyi. Fruits commonly eaten by tamarins contain large seeds surrounded by a fibrous and adhesive pulp or arilate seed coat. They generally swallow seeds and pulp together. Intact seeds are voided over a 1- to 3-h period. Measurements of 132 seeds naturally voided by Panamanian tamarins average 11.2 mm in length and 0.3 g. The greatest number of large seeds contained in the digestive tract of a single animal at one time was 13. In the case of moustached tamarins, we collected 220 seeds. Average seed length is 11.9 mm and average seed weight is 0.3 g. At the time of capture, one animal had 26 seeds in its digestive tract. In both tamarin species, there is evidence of sex-based differences in feeding behavior. Adult female moustached and Panamanian tamarins swallowed and voided seeds of larger size than adult males did. Seed size is positively correlated with pulp weight (p <. 001), therefore females were selecting food items with higher nutritional rewards than adult males did. Given their small body size and relatively short digestive tract, why do tamarins swallow such large seeds? Although several explanations are possible, we propose that the large number and size of undigested seeds continuously passing through the tamarin gut serve a curative role in mechanically dislodging and expelling intestinal parasites—Ancanthocephala (spiny-headed worms)—from their digestive tracts.

Food patch structure and plant resource partitioning in interspecific associations of amazonian tamarins

Avila-Pires’ saddle-back tamarins (Saguinus fuscicollis avilapiresi) and red-cap moustached tamarins (S. mystax pileatus), coexisting in highly stable mixed-species groups, overlapped considerably in their use of plant food resources at an Amazonian terra firme forest site. Overlap between food types consumed by the two species was particularly high during periods of lowest fruit availability, when they resorted to a common food supply, primarily the pod exudates of two emergent species of legume trees (Parkia nitida andParkia pendula) and nectar ofSymphonia globulifera. Within-group interspecific competition did not covary with independent measures of resource availability, contrary to predictions based on resource partitioning models. A greater number of both saddle-back and moustached tamarins were able to feed for longer patch residence periods within larger and more productive food patches, whereas small and clumped patches could be monopolized by the socially and numerically dominant moustached tamarins to the physical exclusion of the smaller-bodied saddle-back tamarins. Overall rates of interspecific aggression were extremely low, however, partly because patches that could be monopolized contributed with a minor proportion of either species’ diet. Saddle-backs foraged at lower levels in the understory and encountered smaller food patches more often, whereas moustached tamarins foraged higher and encountered more larger patches in the middle canopy. Although the two species led one another to differently-sized patches, moustached tamarins initiated most feeding bouts and encountered significantly larger and more productive patches that tended to accommodate the entire mixed-species group. Disadvantages of exploitative and interference feeding competition over plant resources, and advantages of shared knowledge of food patches, are but one component of the overall cost-benefit relationship of interspecific associations in tamarins.

Social and seasonal influences on reproductive biology in male moustached tamarins (Saguinus mystax)

In several primate taxa there is evidence that the social and physical environment can exert a significant effect on reproductive behavior and biology. In this paper we examine social and physiological factors influencing group composition and reproduction in free-ranging moustached tamarin monkeys (Saguinus mystax mystax). This species is characterized by cooperative care of the young and a breeding system that includes both polyandrous and polygyandrous matings. Body measurements collected on adult males residing in multimale groups indicate marked within-group differences in testes volume. In 12 of 17 groups examined, testes volume of at least two resident adult males differed by 21–174%. Among these males, testes volume was not correlated with either body weight or adult age class. We also examine whether factors such as time of year had an effect on reproductive condition. An analysis of body measurements of 128 adult male and 127 adult female moustached tamarins, wild-trapped and released in northeastern Peru, indicates cyclic changes in genital size. For males, mean monthly testes volume in July (712 mm3) was twice that recorded in June (351 mm3). Females exhibited a similar pattern. Although endocrine information on intra- and intersexual social effects on fertility are unavailable for S. mystax, given the high degree of social cooperation and lack of overt aggression among adult male group members, we offer the possibility that resident male moustached tamarins compete for access to the groups' lone breeding female through socially induced reproductive suppression and sperm competition. © 1996 Wiley-Liss, Inc.

Social and seasonal influences on reproductive biology in male moustached tamarins (Saguinus mystax).

In several primate taxa there is evidence that the social and physical environment can exert a significant effect on reproductive behavior and biology. In this paper we examine social and physiological factors influencing group composition and reproduction in free-ranging moustached tamarin monkeys (Saguinus mystax mystax). This species is characterized by cooperative care of the young and a breeding system that includes both polyandrous and polygyandrous matings. Body measurements collected on adult males residing in multimale groups indicate marked within-group differences in testes volume. In 12 of 17 groups examined, testes volume of at least two resident adult males differed by 21-174%. Among these males, testes volume was not correlated with either body weight or adult age class. We also examine whether factors such as time of year had an effect on reproductive condition. An analysis of body measurements of 128 adult male and 127 adult female moustached tamarins, wild-trapped and released in northeastern Peru, indicates cyclic changes in genital size. For males, mean monthly testes volume in July (712 mm3) was twice that recorded in June (351 mm3). Females exhibited a similar pattern. Although endocrine information on intra- and intersexual social effects on fertility are unavailable for S. mystax, given the high degree of social cooperation and lack of overt aggression among adult male group members, we offer the possibility that resident male moustached tamarins compete for access to the groups' lone breeding female through socially induced reproductive suppression and sperm competition. © 1996 Wiley-Liss, Inc.

Social behavior of wild moustached tamarins, Saguinus mystax, at the Estación Biológica Quebrada Blanco, Peruvian Amazonia.

The social behavior in two small, polyandrous groups of moustached tamarins, Saguinus mystax, was studied at the Estación Biológica Quebrada Blanco in northeastern Peru. Allogrooming was the most obvious type of social interaction. Grooming relations were characterized by a strong asymmetry. In both groups, one adult male contributed about 70% of all allogrooming given (in terms of time spent grooming) and allocated his allogrooming evenly to all other group members. Grooming relations between the second adult male and other group members were less intensive. Intragroup agonistic interactions were infrequent, and most of them occurred in the context of feeding on small food resources (fruit, exudate) and during intergroup encounters. Sexual behavior was rare, but at least in one group a tendency existed for the principal groomer to be somewhat more active than the other male. Results are compared with data from other field studies on callitrichid social behavior. Although the label polyandrous correctly describes the demographic structure of many groups, it is not clear whether it is sufficient for understanding the patterning of social relations and thus the social organization of tamarins. © 1996 Wiley-Liss, Inc.

Sleeping habits of tamarins, Saguinus mystax and Saguinus fuscicollis (Mammalia; Primates; Callitrichidae), in north‐eastern Peru

The sleeping habits of moustached tamarins, Saguinus mystax, and saddle‐back tamarins, Saguinus fuscicollis, were studied in northeastern Peru. Five types of sleeping sites were distinguished: 1) Jessenia bataua palms; 2) tree hollows; 3) dense tangles of vegetation; 4) crotches; 5) open horizontal branches. Both tamarin species used Jesseniu‐palms most frequently. Tree hollows ranked second in the saddle‐back tamarins, but were never used by moustached tamarins. Sleeping sites of moustached tamarins were located significantly higher than those of saddle‐back tamarins. Jessenia‐palms used by moustached tamarins were significantly higher than palms from a random transect sample, but this was not the case for Jessenia‐palms used by saddle‐back tamarins. For both species, concealment seems to be more important than height above ground. The maximum number of subsequent nights spent in the same sleeping site was two in moustached tamarins and six in saddle‐back tamarins. The two tamarin species did not compete for sleeping sites. While the general pattern of sleeping site selection conforms to hypotheses predicting safety from predators as a major factor, differences between the two tamarin species reflect general niche differences between them. Most sleeping sites are located in exclusively used parts of the home range. Moustached tamarins generally use sleeping sites that are close to the last feeding site of the afternoon. The distance between simultaneously used sleeping sites of moustached and saddle‐back tamarins are generally close together, which helps to minimize time spent out of interspecific association.

Positional behavior in moustached tamarin monkeys: effects of habitat on locomotor variability and locomotor stability

Abstract Knowledge of the positional behavior of living primates offers significant insight into patterns of habitat utilization, foraging strategies, and locomotor adaptations in fossil primates. Although it is generally assumed that locomotor patterns are strongly constrained by anatomy, few studies have addressed the question of locomotor plasticity and the degree to which patterns of positional behaviour may vary within the same species. In this paper, we provide quantitative data on positional behavior and substrate preference in adult moustached tamarins (Saguinus mystax) inhabiting two structurally distinct forest types in northeastern Peru. Despite major between-site differences in forest structure, tree density, liana density, and the extent of the continuous canopy, overall patterns of positional behavior were virtually identical. At the Padre Isla Field site, quadrupedal progression (55·7%), climbing (5·7%) and leaping (24·8%) accounted for 86·2% of travel. At the Rio Blanco site, these locomotor behaviors (quadrupedal progression, 51·6%; climbing, 10·8%; and leaping, 30·9%) accounted for 93% of travel. Patterns of support preference were more variable, however, and appeared to reflect site-specific differences in forest architecture. The results of this study indicate that both anatomy and local habitat play an important role in directing patterns of positional behavior in moustached tamarins. We argue, however, that locomotor anatomy acts to constrain the efficiency of locomotor choices and that even in forests of different canopy structure and tree density, tamarins negotiate preferred substrates using consistent patterns of positional behavior. Comparisons with other taxa indicate that several species of arboreal primates are similarly characterized by limited between site variability in positional behavior.

Urine washing and related behaviour in wild moustached tamarins,Saguinus mystax (callitrichidae)

Urine washing (UW) and urinating onto hand (UH) are reported for the first time for a wild callitrichid monkey, the moustached tamarin,Saguinus mystax. Both patterns are very rare and no sex difference in frequency is apparent. The temporal distribution shows a maximum of UH/UW around midday when ambient temperature is at maximum and humidity at minimum. No seasonal effects were observed, but any seasonal effect might be masked by the low frequency of UH/UW. UH/UW are not linked to a single behavioural context and may have multiple functions in thermoregulation/water conservation, cleaning, improving grip, and as a social signal.

Primate Responses to Phenological Changes in an Amazonian Terra Firme Forest

The responses of saddleback tamarins Saguinus fuscicollis avilapiresi, moustached tamarins S. mystax pileatus, brown capuchins Cebus apella and gray woolly monkeys Lagothrix lagotricha cana to seasonal changes in plant phenology were examined in undisturbed terra firme forest in the upper Urucu river, Brazilian Amazonia. Primate species fed largely on ripe fruit pulp for most of the year, but shifted to alternative plant resources during the dry season, when the density of fruiting trees and the abundance of ripe fruit reached their lowest levels. The main dry season plant resource used by the two tamarin species was nectar, while those of brown capuchins and woolly monkeys are immature seeds and young foliage, respectively. Exudates of Parkia seedpods were heavily used by all species. Nondietary seasonal adaptations to lean fruit supplies are described for these and other sympatric primate species mainly in terms of pronounced shifts in habitat use and ranging behavior. -from Author

Modeling monkeys: A comparison of computer-generated and naturally occurring foraging patterns in two species of neotropical primates

We present a series of computer-generated foraging models (random movement, olfactory navigation, and spatial memory) designed to examine the manner in which sensory cues and cognitive skills might be used by rainforest monkeys to locate patchily distributed feeding sites. These simulations are compared with data collected in the Amazon Basin of northeastern Peru on the foraging patterns of two species of neotropical primates, the moustached tamarin monkey (Saguinus mystax) and the saddle-back tamarin monkey (Saguinus fuscicollis). The results indicate that, although tamarins may rely on olfactory cues to locate nearby feeding sites, their foraging patterns are better explained by an ability to maintain a detailed spatial map of the location and distribution of hundreds of feeding trees in their home range. There is evidence that such informationis retained for a period of at least several weeks and is used to minimize the distance traveled between widely scattered feeding sites. The use of computer simulations provides a powerful research tool for generating predictive models regarding the role of memory and sensory cues in animal foraging patterns.

Primary renal hemangiosarcoma in a moustached tamarin

A wild-caught adult female Saguinus mystax died after 54 months in captivity. At necropsy, a small reddish zone in the renal cortex of one kidney was shown histologically to be a hemangiosarcoma.

Diet and feeding ecology of saddle‐back (Saguinus fuscicollis) and moustached (S. mystax) tamarins in an Amazonian terra firme forest

The feeding ecology of two small‐bodied primate species—saddle‐back (Saguinus fuscicollis auilapiresi) and moustached tamarins (S. mystax pileatus)—occurring in stable, mixed‐species groups was studied in a terra firme forest site in the upper Urucu River, Amazonas, Brazil. Ecological data are based primarily on one mixed‐species group of 5–8 saddle‐back and 8–10 moustached tamarins. The overall vegetative and animal‐prey components of each tamarin species' diet, their selection of food species, and the seasonal variation in their use of plant resources are described, and compared to those of callitrichids elsewhere. The extremely diverse diet of tamarins included at least 136 tree, 33 vine and liana, 12 epiphyte and nine shrub species, as well as a wide range of prey items. They fed primarily on ripe fruit pulp of most of these species for most of the year, but shifted to floral nectar and plant exudates of a few key plant species during the dry season. Taxonomic overlap in plant diet was nearly complete between the two tamarin species, but they diverged considerably in their prey capture techniques. Saddle‐backs used the low forest understorey, and manipulatively searched for sedentary prey concealed within discrete, usually rigid, microhabitats, whereas moustached tamarins used the midstorey where they visually searched for mobile prey well exposed on foliage. These and other feeding and foraging patterns are discussed in the light of other callitrichid species studied to date.

Anti-predation benefits in a mixed-species group of Amazonian tamarins.

Because of their small body size, tamarins are potentially vulnerable to a wide range of predator species. This paper examines the general patterns of predator avoidance of the Avila-Pires saddle-back tamarin (Saguinus fuscicollis avilapiresi) and the red-cap moustached tamarin (Saguinus mystax pileatus) in the upper Urucu river, Amazonas, Brazil. One highly stable mixed-species group of these species suffered an average of 1 attack by carnivorous raptors every 8.8 days of activity. Although none of these attacks was successful tamarins occasionally fall prey to raptors or terrestrial predators. The two tamarin species exhibited a high degree of coordination in their anti-predation tactics. Saddle-back tamarins accounted for most of the vigilance and detection of terrestrial and scansorial threats, whereas moustached tamarins scanned for and detected most aerial and arboreal threats. Of the two species, however, moustached tamarins contributed a significantly greater proportion of scanning time after predation attempts, during pre-retirement periods and at other times. Moreover, their substantially larger groups (1.6 times larger than those of saddle-back tamarins) accounted for a further increase in their effective vigilance effort. The anti-predation benefits gained by saddle-back tamarins from joining mixed-species groups with moustached tamarins thus appeared to be greater than the reverse, because the latter provide greater protection to the group, particularly against aerial sources of threat. However, the greater vigilance of saddle-back tamarins towards potential terrestrial predators cannot be discounted, because these may on rarer occasions pose a real threat to either species.(ABSTRACT TRUNCATED AT 250 WORDS)

Demographic and reproductive patterns in moustached tamarin monkeys (Saguinus mystax): Implications for reconstructing platyrrhine mating systems.

In this paper we address a series of questions concerning reproductive opportunities, kinship, dispersal, and mating patterns in free-ranging moustached tamarin monkeys (Saguinus mystax). Between 1980 and 1990 information on group size, composition, and migration patterns was collected on marked groups of moustached tamarins inhabiting Padre Isla, an island in the Amazon Basin of northeastern Peru. In 1990, 86% of 114 animals residing in 16 social groups were trapped, examined, and released. Mean group size was 7.0, including 2.2 adult males and 2.0 adult females. None of these groups was characterized by a single adult male-female pair. In groups with more than one adult female, only the oldest female produced offspring. An examination of dispersal patterns indicates that transfers between groups were common and fell into several categories, including immigration of individual males and females, simultaneous transfer of pairs of subadult and/or adult males (sometimes relatives) into the same social groups, and group fissioning in which males and females of the splinter group join another small social group. We have no unambiguous cases of 2 adult/subadult females migrating together into the same social group. All 6 groups for which reproductive data were available were characterized by either a polyandrous or polygynous (polygyandrous) mating pattern. The results of this study indicate that moustached tamarins reside in small multimale multifemale groups that are likely to contain both related and unrelated adult group members. Kinship and social ties among males appear to be stronger and more longlasting than kinship and social ties among females. We contend that the modal mating system of moustached and many other tamarins is not monogamous, and offer the possibility that cooperative infant care and mating system flexibility in callitrichines evolved from a polygynous mating pattern. © 1993 Wiley-Liss, Inc.

Patterns of range use, range defense, and intergroup spacing in moustached tamarin monkeys (Saguinus mystax)

In this paper we examine patterns of group spacing and habitat utilization in neighboring groups of marked free-ranging moustached tamarin monkeys (Saguinus mystax) inhabiting Padre Isla, a small island in the Amazon Basin of northeastern Peru, and describe the set of behavioral mechanisms used by tamarins to maintain the spatial isolation and social integrity of individual groups. Specifically, we address a series of questions regarding the importance of resource defense, mate defense, and territorial defense in intergroup interactions.

Prey-capture benefits in a mixed-species group of Amazonian tamarins, Saguinus fuscicollis and S. mystax

Tamarins of the genus Saguinus feed on a wide range of arthropods and small vertebrates, which compose a critical component of their diet. This paper examines the foraging patterns and capture success of the Avila-Peres saddle-back (S. fuscicollis avilapiresi) and the red-capped moustached tamarin (S. mystax pileatus) in very stable mixed-species groups, and whether and how any foraging benefits for either species resulted from their association. Moustached tamarins actively searched for prey items which were mainly well exposed on the midstorey foliage. Saddle-back tamarins, on the other hand, foraged at lower heights, largely by manipulating a variety of microhabitats potentially concealing embedded prey. The foraging activity of the numerically dominant and larger-bodied moustached tamarins often resulted in prey items escaping to lower substrates, usually the forest leaf-litter. The “beating effect” of this species substantially facilitated captures of large, mobile prey items by saddle-backs, which were highly adept at locating and retrieving flushed prey. It is estimated that, while saddle-backs obtained 66–73% of their prey biomass from flushed items, this proportion was substantially lower (2–9%) for moustached tamarins. Commensal insectivory appears to involve a highly asymmetric benefit to saddle-backs, and a low cost to moustached tamarins, which partly explains the stability of mixed-species groups.

Consequences of Joint-Territoriality in a Mixed-Species Group of Tamarin Monkeys

AbstractGroups of saddle-back (Saguinus fuscicollis) as moustached tamarins (Saguinus mystax) in a western Amazonian forest jointly defended home ranges larger than 100 ha, which were held in common throughout the year. Resources were defended by direct exploitation in extensive areas shared with other groups, or through intensive and frequent intergroup interactions along territorial boundaries. These interactions were expressed primarily during intergroup encounters, and affected the use of space, movements, time budget, and foraging success of tamarins. During encounters, animals of both species spent more time in energetically costly activities, such as rapid travel and intergroup chases, and less time in energetically positive activities, such as feeding and foraging. In addition, foraging success per unit of foraging effort within overlapping areas of the range periphery was lower than in exclusive areas of the range centre, particularly for saddle-back tamarins. The time and energy allocated by moustached tamarins to boundary contests was considerably greater than that of saddle-backs, despite the fact that only the latter species increased its foraging efficiency by shifting from exclusive areas in the group's range to those shared by other groups. This is probably because of saddle-back's greater use of depletable food supplies, such as small fruit patches and small microhabitats containing embedded prey items. These benefits are likely to justify the substantial amount of time and energy invested in territorial defence for both saddle-backs and moustached tamarins, but appeared to be highly asymmetric between species.

Mortality causes of the moustached tamarin (Saguinus mystax) in captivity

From January 1987 to November 1990, 125 adult Saguinus mystax died at the CRCP. Enteritis/colitis (26%), hypoglycemia/cachexia (19%), and parasitic enteritis (13%) were the most common causes of death. Less common were purulent peritonitis (9%), lobular pneumonia (8%), and hemorrhagic gastroenterocolitis (6%). These results confirm the high frequency of gastroenteric lesions reported in Callitrichidae in captivity.

Geophagy in moustached tamarins,Saguinus mystax (platyrrhini: Callitrichidae), at the Río Blanco, Peruvian Amazonia

During a field study at the Rio Blanco in northeastern Peru between June and September 1990, moustached tamarins (Saguinus mystax) were observed to feed on soil material on three different occasions. Soil was taken directly from bare spots of surface soil (two observations) and from the broken mound of leaf-cutting ants (Atta sp.; one observation). Exposed surface soil is rare throughout the study area. Geochemical analyses of the soils that were consumed showed elevated concentrations of several elements in the ant mound sample compared to the other two soil samples. The most likely hypothesis for the function of soil feeding in moustached tamarins is that it serves in mineral supplementation.

Social behaviour and infant carrying in a group of moustached tamarins,Saguinus mystax (primates: Platyrrhini: Callitrichidae), on Padre Isla, Peruvian Amazonia

The social behaviour of a group of eight moustached tamarins,Saguinus mystax, (five males, three females) was studied on Padre Isla in northeastern Peru. About 60% of all allogrooming was done by the two adult males in the group, and about 11% by a young adult female. All other group members groomed very little. The adult breeding female received more grooming than any other group member. After the death of the adult female (preyed upon by an anaconda) the amount of active allogrooming remained constant for all group members except for the young adult female, who increased her contribution to about 30%. Her preferred grooming partner was the subadult female, which generally screamed when being groomed by the young adult female and terminated grooming by going away. This kind of grooming relation is termed “forced grooming” and is interpreted as a possible social control mechanism. The young adult female groomed the adult males more often after the death of the adult female than before. This might have had the function of strengthening the social bond with the adult males and in obtaining the breeding position in the group. After the death of the adult female, the vulva of the young adult female grew to full adult size. Agonistic behaviour was less frequent than allogrooming. Most aggressive interactions (50%) originated from the subadult male of the group. The young adult female was the target of most of these aggressions. Extremely little aggression occurred between the three females. The young adult female was the only individual who tried to emigrate from the group during the study period. Her attempt to join a neighbour group failed due to rejection by all four members of this group. All group members participated in carrying an infant, but the adult males and the young adult female carried most frequently. Contribution to infant carrying varied with the infant's age.