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Goeldi’s monkey (Callimico goeldii ) is closely related to marmosets and tamarins. Like marmosets and tamarins, C. goeldii lives in family groups, and fathers and older offspring (helpers) participate in infant carrying. In contrast to the typical twin births in marmosets and tamarins, C. goeldii has only single offspring, and paternal carrying is delayed. We studied infant carrying following 26 births in eight groups of C. goeldii , testing hypotheses proposed in the literature on infant carrying in marmosets and tamarins. The infant was carried exclusively by the mother for the first 26.3 days after birth. Afterwards other group members participated in infant carrying. Whereas the C. goeldii mother is always the main carrier, the father does not always carry more than helpers. In contrast to other callitrichids, age and sex of sibling helpers was not found to have an effect on the participation in infant carrying. The participation in infant carrying in Callimico indicated intraindividual consistency, i.e., the amount of infant carrying performed by fathers and helpers following one birth correlated significantly with the amount of infant carrying of the same individuals following the next birth. We found a significant negative correlation between parental infant carrying and group size, indicating that helpers really do help, sharing the carrying burden with their parents. This is attributed to a clear trend for a reduction in maternal carrying in the presence of helpers, whereas fathers did not benefit from helpers. We conclude that the infant-carrying pattern in C. goeldii is different from the infant-carrying pattern in marmosets and tamarins. The main differences were that the mother instead of the father is the main carrier, and that there is a clear time delay between infant birth and when the father and helpers participate in infant carrying. Am. J. Primatol. 53:57–67, 2001. © 2001 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] more...

The article presents abstracts on several topics which include the Continuity and change in Late-Prehistoric Germany, An analysis of the pathology of the Krapina Neandertals, and the Scaling and size reduction in tamarins. more...

Investigates whether scent marking has a function in territorial advertisement and defence in wild moustached tamarins. Defensibility of home range; Correlation between frequency of quadrat occupation and frequency of scent marking; Spatial distribution of scent marking; Function of scent marking mainly in intersexual communication. more...

The foveal specializations of five New World monkeys, the marmoset, Callithrix jacchus; the golden-handed tamarin, Saguinus midas niger; the squirrel monkey, Saimiri ustius; the capuchin monkey, Cebus apella; and the howler monkey, Alouatta caraya were compared. Although retinal area varies by over a factor of two in these monkeys, the area of the fovea does not covary with retinal area and remains approximately the same absolute size, as measured by the dimensions of the high density region of cones, or the rod-free region. This constancy in foveal size also holds for rhesus monkeys and humans, bringing the variation in retinal area to a factor of five. Alouatta caraya is unusual, distinguished by a very high central cone density and a small rod-free zone. Physiological constraints that might limit foveal area over a wide range of eye sizes are considered.Copyright © 2001 S. Karger AG, Basel [ABSTRACT FROM AUTHOR] more...

The birth of emperor tamarin (Saguinus imperator ) twins was observed in the wild. The mother was a member of lone pair in a marked population of emperor tamarins in the Manu National Park, Peru. This report describes the birth and provides subsequent information on infant care and survival. Despite some difficulties, this lone pair of relatively young, primiparous emperor tamarins was able to successfully raise twin offspring to the age of at least 1 month. Am. J. Primatol. 52:107–113, 2000. © 2000 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] more...

The provision of novel objects allows one to probe for behavioural differences among species. This is particularly relevant when studying species that form mixed-species groups, as divergent responses may provide clues to the advantages that individuals gain from associating. We compared the responsiveness to novel objects in captive single- and mixed-species groups of saddleback (Saguinus fuscicollis) and red-bellied (Saguinus labiatus) tamarins to determine the influence of a congener. We tested groups with novel objects placed near the top, the middle, and on the floor of their enclosures and measured latency to approach and touch them. We tested predictions related to differences in lifestyle patterns under natural conditions. As we predicted, S.labiatus, which usually occur at a higher mean height in the forest than their congeners, responded to objects placed near the top of the enclosure significantly quicker in both single- and mixed-species groups. S. fuscicollis responded to objects placed on the floor quicker, and in mixed-species groups S. fuscicollis approached them before S. labiatus did. There were specific differences in median touch–approach time (T-A): Saguinus fuscicollis had a shorter T-A time than that of S. labiatus , which can be related to their manipulative foraging style. Reaction times decreased in mixed-species trials for both species, suggesting that the reaction of one species may effect the congener. Both species may benefit through association, though the dominance of Saguinus labiatus over S. fuscicollis may limit the advantages to S. fuscicollis . Over all our study supports the idea that cross-specific social facilitation is an important consequence of mixed-species groups of Saguinus . [ABSTRACT FROM AUTHOR] more...

Reproduction is restricted to a small number of animals within both captive and wild groups of callitrichid monkeys (marmosets and tamarins). Sexual development of nonbreeding group members might differ from that of active breeders. Measurements of physical growth typically involve animal handling. However, capture and restraint of callitrichid monkeys can disrupt natural behaviors and physiology. This study introduces a method for estimating size of external genitalia by measuring frontal scrotum width of unrestrained cotton-top tamarin males. We examined whether scrotum width was a reliable indicator of testis size, and whether the method provided information useful for comparisons of growth and development among individuals. Animals were lured to a standardized position, and maximum width of the scrotum was systematically compared to a card with a series of rectangles graded in 1 mm increments. Card measures were validated with caliper measurements of scrotum width and testicle dimensions. Regressions of testes dimensions measured by caliper on scrotum width measured by card were between 82 and 93%, suggesting that measures of frontal scrotum width provide consistent estimates of relative testis sizes. The period of rapid growth ended by roughly two years of age, after which scrotum size did not differ from that of breeding males. Am. J. Primatol. 51:187–195, 2000. © 2000 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] more...

Vertebrate predation was examined in sympatric moustached tamarins (Saguinus mystax ) and saddle-back tamarins (Saguinus fuscicollis ) in the Amazon rainforest of northeastern Peru. Both species prey on frogs and lizards, and very rarely on nestling birds. As a result of divergent foraging strategies, S. mystax primarily exploited frogs at higher strata of the forest, while S. fuscicollis predominantly preyed on reptiles in the lower strata and on the ground. This difference may strengthen the niche differentiation between these two tamarin species that exists with regard to other prey. Am. J. Primatol. 51:153–158, 2000. © 2000 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] more...

In species in which paternal care has an important impact on the offspring's fitness, concealment of reproductive status has been proposed as a strategy employed by females to prevent males from practicing desertion and polygamy, which would then lead to monogamous or polyandrous mating systems or both. We investigated whether the female's reproductive status is being concealed in golden-headed lion tamarins, which exhibit extensive paternal care and a mainly monogamous/polyandrous mating system. We used a combination of behavioral observations and endocrine data to determine female reproductive status and to examine changes in sociosexual behaviors over the ovarian cycle and between conceptive and nonconceptive cycles. Females clearly signaled their reproductive status by way of proceptive sexual presenting. Males showed increased frequencies of anogenital sniffing and mounting during the fertile period, indicating that they detected changes in olfactory and behavioral cues emitted by females, and they adjusted their mounting behavior accordingly. Males and females also remained in closer proximity before and during the fertile period, which suggests the existence of mate guarding. We discuss a possible function of behavioral advertisement of reproductive status in shaping the mating system in Leontopithecus chrysomelas . [ABSTRACT FROM AUTHOR] more...

We carried out a 4-month census of primates in the Pando Department of northern Bolivia with special emphasis on Saguinus species. Contrary to a previous report by Izawa and Bejarano (1981), there was no evidence for the presence of the two populations of Saguinus mystax that they reported, or that Lagothrix occurs in the Pando. In addition, we found the distribution of Saguinus imperator to be more restricted than they suggested. We confirm the presence of Cebuella south of the Río Tahuamanu (cf. Brown and Rumiz, 1986) and report two new locations for Callimico goeldii . We present data on group sizes, habitat utilization, and locomotor behavior of the primates and compare them with previous studies in the Pando. Differences in body size, diet, foraging techniques, and vertical use of the forest appear to be key factors in both sympatry and in the formation of polyspecific associations. [ABSTRACT FROM AUTHOR] more...

To examine the development of production, comprehension and usage of chirp vocalizations in infant cotton-top tamarins, we designed four experimental settings to elicit five of the eight chirp types of adult cotton-top tamarins. We tested non-reproductive adult pairs and family groups before and after the birth of infants. We observed responses of infants in family groups during the first 20 weeks following birth. The five chirp types were rarely given in control conditions, but each type occurred at significant levels among adults and subadults immediately following presentation of an appropriate stimulus. Each chirp type was specific to one experimental manipulation. We found no differences between non-reproductive pairs and families prior to the birth of infants, but two chirp types were produced at significantly lower rates following the birth of infants. Infants produced a form of chirp (prototype chirp) not seen in adults, but infants rarely produced adult forms of chirps. If an adult-appropriate chirp was produced by an infant in one session, there was a low probability of that chirp appearing in subsequent tests with the same infant. Infants used most frequently the form of chirp (D chirp) that was most frequently directed toward them by adults, and infants reduced their rates of prototype chirps following presentation of visual and auditory alarm stimuli. Although infant tamarins under 20 weeks of age appear unable to use adult types of chirps consistently, they did produce chirps with adult form, and they appeared to show some comprehension of chirps produced by adults. [ABSTRACT FROM AUTHOR] more...

Presents information on a study which examined the constancy of variation and covariation assumptions on tamarin species using the principal component analysis and matrix correlations. Research methodology; Results and discussion of the study; Conclusions. more...

An infanticide was observed in a group of wild saddle-back tamarins, Saguinus fuscicollis . The newborn singleton was killed by its mother after it had fallen from the carrier several times. This infanticide may represent a case of parental manipulation: the mother terminated investment in an offspring that probably had a low chance of survival. Also, stress associated with the simultaneous pregnancy of another adult female in the group may have played a role. Am. J. Primatol. 50:153–157, 2000. © 2000 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] more...

I provide the first comprehensive data on the composition and mineral content of exudates eaten by saddleback (Saguinus fuscicollis ) and mustached tamarins (S. mystax ) and assess Garber's (1984; 1993) hypotheses on the potential nutritional importance of exudates in the diet of tamarins. In accordance with his initial findings, nutritional analyses show that the gums consumed are relatively high in calcium and may serve to balance a diet otherwise low in this mineral and high in phosphorus. However, the data on the seasonal variation in the amount consumed do not support the hypothesis that exudates are of particular nutritional importance during the later stages of gestation or lactation for saddleback or mustached tamarins. [ABSTRACT FROM AUTHOR] more...

In this paper, we report on a craniometric analysis comparing the species of lion tamarins, Leontopithecus Lesson, 1840. Seventeen cranial and mandibular measures were taken on skulls of 59 adult crania: 20 L. rosalia (14 females and 6 males); 13 L. chrysomelas (6 females and 7 males); 23 L. chrysopygus (8 females and 15 males), and 3 L. caissara (1 female and 2 males). All specimens were from the Rio de Janeiro Primate Center (CPRJ-FEEMA, Brazil), except the specimens of L. caissara . Statistical treatment involved a one-way analysis of variance (the Bonferroni test) and discriminant analysis, comparing cranium and mandibles separately to determine variables which best distinguished groups and to group the specimens, using size corrected methods. The Mahalanobis distance was computed from the centroids of each group. Seven measures distinguished females of L. chrysopygus with L. rosalia , six to L. rosalia with L. chrysomelas , and L. chrysopygus with L. chrysomelas . In males, the numbers of measures statistically different were 5, 4, and 3 of the pairwise comparisons above mentioned. Cranial base length and orbital breadth were the only measures that were significantly different in all three dyads, considering both sexes. For the cranium, function 1 of the Discriminant Analysis accounted for 52.4% of the variance and function 2 accounted for 40.3%. Both functions exhibited a significant value for Wilks' lambda (P <0.0001) and 96.6% of specimens were correctly classified. For the mandible, the first two functions provided a significant discrimination 51.1% and 44.9%, respectively, and 69.5% of the correct classification. Orbital breadth and cranial base length contributed most in the cranial analysis, while mandibular length and mandibular body height to mandibular ones. The analyses performed in this study (univariate and multivariate) demonstrated that cranial and mandibular morphology is significantly different among species of Leontopithecus . Despite of sample size, L. caissara shows morphological distances to L. chrysopygus in cranial analysis. However, other investigations are necessary to confirm this. Am. J. Primatol. 48:185–196, 1999. © 1999 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] more...

Infant-carrying behavior among callitrichids seems to be a costly activity. Costs have been related to the physical efforts of carrying the weight of very heavy infants and to the resulting reduction in foraging efficiency. However, the costs of carrying in terms of the physical consequences for carriers have not previously been assessed. In this study, we have regarded weight loss in infant carriers as a measure of costs. We studied five families of cotton-top tamarins (Saguinus oedipus ) during the first 9 weeks following the birth of infants. Captive-breeding conditions were required so that body weight could be measured frequently. To avoid inflicting undue stress on the subject animals, we used a noninvasive method for weighing the tamarins. Differences in carrying contribution were found amongst fathers and male and female helpers, with female helpers contributing less. We have found that carrying infants in the cotton-top tamarins is an activity that produces a weight loss. Fathers and male helpers go through a maximal body weight loss. While carrying, the tamarins also decrease food intake. However, no relationship was found between contribution to carrying and feeding time or in energetic intake during feeding observations. Thus, it seems that a direct relation doesn't exist between the observations of feeding and weight loss. Fathers increase their contribution to carrying during mothers' periovulatory periods. In this period, male helpers and especially fathers go through a maximal body weight loss. We found body weight losses of up to 11.3% in one subadult male and 9.1percnt; in a father during the fifth week. No changes occurred in food intake in fathers or other male helpers during this period. During periovulatory periods, mothers carried less frequently but did increase their food intake. They gained weight from the second week after birth onward, especially during the periovulatory period. It seems that the infant-carrying behavior of fathers and male helpers may contribute to the improvement of the mothers' physical condition after birth and therefore may support a consecutive pregnancy. Am. J. Primatol. 48:99–111, 1999. © 1999 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] more...

Presents an experiment in which an object retrieval task is used to examine inhibition of prepotent inappropriate responses in problem-solving in cotton-top tamarins. Difficulty of retrieval from a box when the opening was on the side; Effect of prior training with an opaque box. more...

Adult-infant food-sharing behavior is a major component of the infant care strategies of callitrichids (marmosets and tamarins). It is particularly well-developed in cotton-top tamarins ( Saguinus Oedipus) and lion tamarins ( Leontopithecus spp), which show frequent adult-initiated food offering, as well as sharing of food in response to begging by infants. This report documents a case of cross-generic food sharing, in which a male golden-headed lion tamarin ( Leontopithecus chrysomelas) shared food with an infant cotton-top tamarin. The lion tamarin provided more food to the infant than its mother did. This emphasizes the importance of this behavior in the reproductive strategies of the communally-rearing Callitrichidae and raises questions about mechanisms that underly it. [ABSTRACT FROM AUTHOR] more...

Investigates intra- and inter-specific social learning in two species of New World monkey, the saddle-backed tamarin and the red-bellied tamarin, which form stable and permanent mixed-species troops in the wild. Issue of whether individuals succeeded at the task more quickly after having observed demonstrators; Comparison of performance between species. more...

Describes evidence from experimental studies in which adult female tamarins (Saguinus) and marmosets (Callithrix) demonstrate priority of access to food that is spatially and temporarily restricted. Differences in behavioral strategies between both reproductive and non-reproductive females; Factors that influence differences in responsiveness. more...

Examines the factors influencing the sleeping site selection by tamarins. Display of behaviors reducing predation risk; Proximity to food resources; Knowledge of previous use of the site.

In many species of birds and mammals with a co-operative breeding and rearing system, offspring survival is positively related to the number of helpers. In the New World callitrichine primates (marmosets and tamarins), adult males are considered as particularly valuable helpers, and female reproductive success may depend strongly on the males' contribution to infant care. We analysed the number of offspring (infants, juveniles) in groups of wild pygmy marmosets, Cebuella pygmaea (Callitrichinae, Cebidae, Primates), in relation to the number of adult males and to the number of adult and subadult group members. In contrast to other callitrichines with a co-operative system of infant care, no relationship was found between the number of adult males and the number of infants and offspring. However, there was a significant positive relationship between the number of juveniles and the number of adult and subadult group members. The lack of a relationship between infant and adult-male number is interpreted as resulting from the reduced importance of adult males as helpers in pygmy marmosets in comparison to other callitrichines, probably due to the reduced costs of infant care. The relationship between the number of juveniles and the number of adult and subadult group members is in accordance with increased offspring survival in larger groups, as observed in other primates. [ABSTRACT FROM AUTHOR] more...

Abstract 14-34 [ABSTRACT FROM AUTHOR]

Presents several abstracts on primatology. Sperm competition; Hand preference in bilaterally skilled bonnet macaques Macaca radiata; Identification and selection of fur rubbing materials by white-faced capuchin monkeys (Cebus capucinus); Hand specialization and mixed-species associations in tamarins; Others. more...

Reproductive patterns of wild cotton-top tamarin (Saguinus oedipus ) females located in La Reserva Forestal Protectora Serranía de Coraza-Montes de María in Colosó, Colombia, were examined using long-term behavioral observations and fecal steroid analysis. Using an enzyme immunoassay, we analyzed fecal samples for E[sub 1] C and PdG. Comparisons of reproductive cycles of a reproductively active female and her daughters were made. An inhibition of ovarian cycles has been observed in daughters living in their families. However, daughters also exhibited normal ovarian cycling that subsequently resulted in pregnancy. Factors influencing the fertility are discussed as they relate to the reproductive strategies of wild cotton-top tamarin females. Am. J. Primatol. 43:329–337, 1997. © 1997 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] more...

The karyotypes of two taxa of genus Leontopithecus (rosalia and chrysomelas ) are studied. Their G-, C- and NOR-banding patterns are compared with those of representatives of the genus Saguinus to determine chromosomal similarities and differences between the two genera and thus contribute to explaining phylogenetic relations between the tamarins. Leontopithecus , like the Saguinus , presents 2n = 46, 14 autosomes plus the Y acrocentric and 30 autosomes plus the X biarmed. No chromosomal rearrangement distinguishes the karyotypes of the representatives of genus Leontopithecus or genus Saguinus . The two genera are distinguished from each other by a paracentric inversion and pericentric inversions on at least four pairs of acrocentric autosomes, displacing the NORs of the small short arms in Leontopithecus to the proximal region of the long arms in Saguinus or vice versa. The tamarins are also distinguished by the distribution of noncentromeric constitutive heterochromatin. The data obtained indicate that the two tamarin genera are closely related chromosomally, suggesting that they probably originated from the same ancestral branch. Am. J. Primatol. 43:265–276, 1997. © 1997 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] more...

Despite the importance of Callitrichid primates in both biomedical and conservation research, practical and reliable immunoassays for the measurement of follicle-stimulating hormone (FSH) have not yet been described. A panel of monoclonal antibodies against specific peptide fragments within either the alpha or beta subunit of human FSH was evaluated for their ability to recognize FSH from Callitrichid and other New World primates. One of these, monoclonal antibody 46.3h6.b7 raised against human FSH, was selected due to its ability to recognize marmoset monkey FSH and its low crossreactivity with other gonadotrophins. The antibody formed the basis of an enzymeimmunoassay using a highly purified human urinary FSH (Metrodin®, Serono) preparation coupled to biotin as label and unmodified as standard. After 24 h incubation, antibody bound label was visualized by addition of streptavidin-peroxidase followed by the appropriate substrate. Parallelism was obtained between the standard and dilutions of pituitary extracts, urine and plasma from the common marmoset (Callithrix jacchus ) as well as from two tamarin species (Saguinus fuscicollis and S. oedipus ) and one squirrel monkey (Saimiri sciureus ). Profiles of plasma and urinary FSH during the follicular phase are shown for two individual marmosets. The ability to measure FSH in Callitrichidae provides new opportunities for studies of the reproductive biology of these New World primate species. Am. J. Primatol. 41:179–193, 1997. © 1997 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] more...

Estimates of the chronological age for animals of unknown age provide useful information for medical, demographic, and evolutionary studies. Skeletal development, as indicated by epiphyseal closure, can be used to estimate an animal's chronological age or specify its stage of development. Many studies of Primate skeletal development have used animals of unknown age, with the order of epiphyseal closure providing a relative age for each animal. This study examines the age of epiphyseal closure at 22 epiphyseal sites using animals of known age at death in three calitrichid species (Saguinus fuscicollis, Saguinus oedipus , and Callithrix jacchus ). The observed average age of epiphyseal closure is similar in these tamarins and marmosets. There is a significant difference in rate of development between the species. Regression equations can predict the age of unknown animals to within 4.8 months for S. fuscicollis , 8.6 months for S. oedipus , and 7.6 months for C. jacchus (twice the standard error of the estimate). These age estimates allow us to determine if an animal is relatively mature or immature, but are largely unacceptable for studies in which precise age estimates are necessary. The order of epiphyseal closure is similar across 11 monkey species (using additional data from published literature) and supports the suggestion of a general pattern in Primate skeletal development. Am. J. Primatol. 41:129–139, 1997. © 1997 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] more...

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. [ABSTRACT FROM AUTHOR] more...

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. [ABSTRACT FROM AUTHOR] more...

Groups of individual marked cotton-top tamarins (Saguinus oedipus), located in La Reserva Forestal Protectora Serranía de Coraza-Montes de Marí in Colosó Colombia, were studied over a period of 5 years. Data on group composition, stability, birthing seasons, and dispersal patterns are used to examine the reproductive strategies and tactics used by males and females. Both monogamous groups and groups containing two pregnant females have been observed. All groups contained at least one adult female and male, with several groups containing several adult males and females. Both males and females dispersed to neighboring groups, and there were no sex differences in rates of emigration. Males were more likely to immigrate into a new group following the death/emigration of a resident male. Females appeared to tolerate immigrating females but would actively defend their breeding position during fertile periods. [ABSTRACT FROM AUTHOR] more...

We monitored a population of four to seven groups of individually marked saddle-back tamarins (Saguinus fuscicollis; Callitrichidae) at the Cocha Cashu Biological Station in Peru's Manu National Park every year from 1979 through 1992. In this paper we use data on life histories, group compositions, group formations, and dispersal patterns collected during these 13 years to examine the reproductive strategies of males and females. Group compositions and mating patterns were quite variable in this population, with both monogamy and cooperative polyandry common. In polyandrous groups, two males shared a female's copulations and cooperatively cared for her young. Although most groups contained a single breeding female, we recorded four cases in which secondary females successfully reared young. Most young females appeared to wait in their natal groups for the first opportunity to fill a primary breeding position in their own or a neighboring group. Females that acquired primary breeding positions maintained those positions for a mean of 3 years. No female was observed to transfer between groups a second time. Variation in female lifetime reproductive success was high. Half of the females marked as juveniles never bred; the other half produced an average of 3.5 young. A paucity of female breeding opportunities may explain the high mortality of females between 2.6 and 4.5 years of age and the resulting male-biased adult sex ratio. The majority of groups contained more than one probable male breeder. Polyandrous groups included both related and unrelated males. Behavioral differences between Cocha Cashu tamarins and other studied populations may result from the pressures of living in an environment inhabited by nine other primate species and numerous predators. [ABSTRACT FROM AUTHOR] more...

A field study of Saguinus nigricollis graellsi in the Cuyabeno Faunal Production Reserve. Ecuadorian Amazonia, established the characteristics of the home range and some reproductive aspects of the species. Field data were collected in two climatic seasons: dry, from December 1989 through March 1990, and rainy, from May through August 1990. Eight groups visited and/or lived in the study area during the dry season and ten during the rainy season. (Group sizes ranged from two to nine individuals Population density was estimated at 22-33 individuals per square km. The central group, which was followed intensively, had a home range which included both flooded and non-flooded forests. Terra firmer forest was most used by the species. The home range of this group was reduced from 56.2 hectares (ha) in the dry season to 41.7 ha in the rainy season, probably as a result of a differential distribution of food plants between seasons. The presence of dense undergrowth where monkeys could hide to avoid predation and/or a high concentration of food plants seem related to the preferential use of certain areas in the home range. The home ranges of neighboring groups overlapped considerably and peaceful temporary large groups were frequently observed. A generalized birth peak occurred in January 1990, dry season In June 1990, rainy season, 40% of the groups exhibited a second birth peak. This reproductive bimodality of S. nigrioltis graellsi indicates a high productivity of the forests at the Cuyabeno site. [ABSTRACT FROM AUTHOR] more...

The effect of hybridization on infant survival was investigated in subspecific crosses of the saddle-back tamarin (Saguinus fuscicollis) at the Oak Ridge Associated Universities (ORAU) Marmoset Research Center (Oak Ridge, TN). Cox Proportional Hazards Regression was used to compare infant survival between 1) pure subspecies, 2) F1, F2, and backcrossed hybrids, and 3) hybrids and their parental subspecies. Also, effects of management changes, sex, and litter size on infant survival were investigated. There were no significant differences in infant survival between the pure subspecies. Also, degree of hybridization (F1, F2, or backcross) did not have a significant effect on infant survival. Progeny of hybrid crosses between S. f. lagonotus and S. f. illigeri was found to have significantly (P < 0.05) higher infant survival than both of their parental subspecies. Individuals born after diet and management changes in the colony had significantly (P < 0.05) higher survival than those born before. There were no significant sex differences in infant survival. Individuals born into triplet litters had significantly (P < 0.05) lower survival than those born into twin litters. These results show heterosis (hybrid vigor) for infant survival in one subspecific S. fuscicollis cross (S.f. lagonotus × S.f. illigeri). The results suggest genetic divergence between the subspecies populations and possible reproductive isolation in the wild. [ABSTRACT FROM AUTHOR] more...

Direct measurements of urinary immunoreactive estrone conjugates (E1C) and pregnanediol glucuronide (PdG), were applied to monitoring the ovarian cycle (n = 9) and pregnancy (3 full term pregnancies, 2 mid-term abortions) in Saguinus fuscicollis. During the ovarian cycle, urinary E1C concentrations revealed a high degree of day-to-day variability and appeared to be uninformative in reflecting cyclic ovarian function. In contrast, PdG was a reliable indicator of ovarian cyclicity with excretion patterns corresponding well with plasma progesterone profiles. Luteal phase PdG concentrations were on average 4-7-fold higher than corresponding follicular phase values. On the basis of changes in circulating progesterone, a mean cycle length of 25.7 ± 1.0 days with an average follicular phase of 7.1 ± 0.6 days and a mean luteal phase of 18.6 ± 0.7 days was found (n = 14 cycles). Following conception, both urinary steroid conjugate concentrations increased and elevated levels were maintained beyond the normal luteal phase length, allowing pregnancy to be determined at around day 25-30. During mid- to late pregnancy, PdG levels declined while E1C concentrations continued to be elevated until approximately 6 weeks before parturition when a decrease occurred. Both hormones showed a clear and rapid fall to follicular phase values following termination of pregnancy at either parturition or mid-term abortion. Post partum ovulations (n = 5) occurred on average 17-18 days following birth with four ovulations leading to conceptions. The results demonstrate the potential of urinary steroid conjugate analysis as a practical and reliable method for non-invasive monitoring of reproductive status in the female saddle-back tamarin. [ABSTRACT FROM AUTHOR] more...

Tamarins and marmosets (subfamily: Callitrichinae) are members of an ecologically and behaviorally diverse radiation of small-bodied New World monkeys characterized by the production of twin offspring, intense female reproductive competition, reproductive suppression, cooperative infant care and evidence of what has been described as a highly flexible system of mating. In this review, I offer a phylogenetic approach to the study of callitrichine reproduction and mating systems. Beginning with the assumption that Callimico most closely resembles the ancestral tamarin and marmoset condition. I identify a set of primitive callitrichine behavioral and reproductive character states and reconstruct the sequence of derived behavioral and reproductive changes that define the basic social systems of Saguinus, Leontopithecus, Callithrix, and Cebuella. It is proposed that ancestral callitrichines lived in small multimale multifemale groups characterized by 1 or more reproductively active females, a single offspring at birth, rapid postnatal growth, delayed nonmaternal caregiving, and a polygynous mating pattern. The evolution of twinning in the common ancestor of all extant tamarins and marmosets increased the overall costs of infant care, resulting in enhanced female reproductive competition and a greater role for group members in providing for the young. Specialized mechanisms of female reproductive competition appear to have evolved twice in callitrichine evolution. In the lineage leading to Leontopithecus, high levels of female intrasexual aggression and ovulatory synchrony play a primary role in the social control of fertility. In Saguinus, Callithrix, and Cebuella, female reproductive suppression has a stronger physiological basis, resulting in hormonally mediated infertility in subordinate adult females. In addition to having important implications for understanding differences in callitrichine breeding systems, these data suggest that Leontopithecus separated from the callitrichin line prior to the radiation of other tamarin and marmoset taxa. [ABSTRACT FROM AUTHOR] more...

Data on the ecology, demography, and morphology of 465 golden lion tamarins in 22 wild groups suggest that avoidance of reproduction and weaning of infants during the dry season shaped the pattern of female reproduction. Post-partum estrus may have evolved to allow females to produce and wean two successive litters during the 7-month season of abundant food resources. Support for these hypotheses includes observations that nearly all births, lactation, and weaning of infants occurred during the wet season, a period of relatively abundant trophic resources. Litter sizes in the wide were smaller than for the captive population. Evidence that food limitation may have a greater negative impact on young juveniles than lactating females includes observations that female weight did not decrease with lactation, and that many births occurred during the transition between dry and wet seasons. Juveniles gained less weight during the dry season than during the wet season; however, there was no significant difference between weights of adults born early vs. late in the wet season. For females producing two litters/year, litter size and infant mortality did not differ for litters born early and late in the wet season. Adult males gained weight before and lost weight during the month of highest probability of female estrus, suggesting that competition for mates is energetically expansive for males. Although resources were abundant, adult males did not gain weight during months when most infant carrying took place, suggesting that this activity is also energetically expensive. [ABSTRACT FROM AUTHOR] more...

Infant marmosets and tamarins (Callitrichidae) frequently receive food from older group members. Three possible functions of food sharing in lion tamarins were examined experimentally. The first hypothesis, that food sharing ensures that infants receive sufficient food even if it is difficult for them to acquire it themselves, was tested by varying the ease with which infants could reach a food source. When access to food was restricted, infants fed themselves less, received more food from others, and had a higher success rate in begging attempts. The second hypothesis, that food sharing helps teach infants an appropriate diet, was tested by presenting fruits that were novel to infants. Although infants fed themselves less under these conditions, adults were Less likely to share novel foods than familiar foods. The final experiment compared food sharing when food was abundant with behavior when food items were presented singly. Infants fed themselves less and received more food from others when food items were rare. These results suggest that food sharing in lion tamarinds helps to ensure that infants receive adequate amounts of food which is difficult to locate or acquire, but that it is not involved in teaching infants which foods they should eat. [ABSTRACT FROM AUTHOR] more...

A radioirnniunological method for measuring urinary luteiniting hormone (LH) and chorionic gonadotropin (CG) excretion in the family Callitrichidse is described. The method uses a monoclonal antibody that will be available in virtually unlimited quantity. Several polyclonal antisera that have been useful for the detection of callitrichid gonadotropins are near depletion. The monoclonal antibody-based RIA provided similar results when compared with the mouse Leydig cell bioassay for LH and a previously validated polyclonal antibody-based RIA. When the inonoclonal antibody is used for linmunodetection of Saguinus oedipus LH by non-reducing SDS-PAGE, a single entity is recognized that corresponds with the molecular weight range of bioactive LH and appears to be in the normal range for LH in nonhuman primates. LH and CG were detected by the monodonal antibody-based RIA in urine from representatives of species from all genera of callitrichids. Hormonal profiles of daily urine samples revealed the detection of the preovulatory LH surge by both RIA methods in the cotton-top tamarin (Saguinus oedipus) and pygmy marmoset (Cebuella pygmea) and the increase in CG due to pregnancy in both species. Serial dilutions of midcycle and pregnancy urine from Saguinus, Callithrix, Leontopithecus, and Cebuella exhibited parallelism when compared with our in-house reference standard of rhesus monkey CG. Cultured Saguinus oedipus pituitary cells showed an increased release of LH when challenged by gonadotropin releasing hormone (GnRH) providing further support that the monoclonal antibody-based RIA measures LH in this species. [ABSTRACT FROM AUTHOR] more...

We present reliable field techniques for capturing, anesthetizing, and identifying individual cotton-top tamarine (saguinus oedipus oedipus). A new technique is presented for radio-tracking small bodied primates. A backpack-style harness was designed to carry a transmitter. This system appears effective in minimizing potential injury and does not appear to interfere with the normal behavior of the animal. [ABSTRACT FROM AUTHOR] more...

Five parous, cycling cotton-top tamarin females were used to compare circulating and urinary profiles of the major reproductive hormones during the ovarian cycle. Blood samples were collected on unanesthetized, hand restrained females three times per week for 25 days and first morning void urine was collected daily for 30-40 days including the serum sampling period. Serum and urine samples were analyzed for estrone, estradiol, and bioactive LH. Additionally, serum was analyzed for progesterone and urine for estrone conjugates (EIG) and immunoreactive LH. Both serum and urinary hormonal profiles revealed ovarian cyclicity in four females; the fifth one stopped cycling during the study. All hormones were referenced to the urinary immunoreactive LH peak. Urinary estrone conjugates followed similar profiles to serum progesterone. Progesterone levels increased two- to threefold on the day of the urinary immunoreactive LH peak. Peak levels of circulating bioactive LH occurred on the same day or the day preceding the urinary bioactive and immunoreactive LH peak for all four cycling females. Serum estradiol levels rose during the follicular phase and peaked prior to or on the day of the urinary LH peak while urinary estradiol levels did not rise until the day of the urinary LH peak. Serum and urinary estrone levels did not rise until the day of the urinary LH peak and remained high throughout the luteal phase. The measurement of urinary LH corresponded well with serum LH, establishing urinary LH as an important hormone for monitoring the ovulation in the tamarin. The highest circulating estradiol concentrations were found in the follicular phase of the cycle, but estradiol did not appear in urine during the follicular phase of the cycle. Elevated estrone levels occur during the luteal phase following the progesterone pattern, and therefore elevated urinary concentrations of estrone and estrone conjugates may be indicative of luteal function. [ABSTRACT FROM AUTHOR] more...

The subspecies of saddle-back tamarins (Saguinus fuscicollis) are known to be chromatically and morphologically diverse but little is known of the genetic basis for the observed morphological variation. The morphology of first generation subspecific hybrids can be compared to that of the parental subspecies to provide information on the extent and nature of genetic differences in morphology between subspecies. We compare two groups of saddle-back tamarin hybrids (S.f. illigeri x S.f. lagonotus and S.f. illigeri x S.f. leucogenys) to pure-bred members of their parental subspecies. These crosses were examined for heterosis, caused by allele frequency differences between the subspecies in combination with directional dominance. Thirty-nine craniofacial measurements were derived from three-dimensional coordinates of landmarks on 355 adult tamarin skulls. these measurements were corrected for sex differences and differences due to environment (wild-derived vs. laboratory-born) prior to analysis of hybridity. Sex differences were minimal for these traits. Environment had a more significant effect on craniofacial morphology. Laboratory environments produce larger faces but smaller orbits, anterior cranial vaults, and cranial bases. Significant heterosis was found for many individual traits and for the first principal component representing size and size-related shape measurements in the S.F illigeri x S.f., lagonotus cross. The smaller samples involved in the S.f. illigeri x S.f., leucogenys cross led to a much lower number of statistically significant results, although most traits did display heterosis. Heterosis for craniofacial size was nearly statistically significant. These results suggest that there are large differences in allele frequencies among these subspecies of saddle-back tamarin for genes affecting craniofacial morphology. Based on these data we suggest that these subspecies are likely to be independent, largely isolated, evolutionary units. [ABSTRACT FROM AUTHOR] more...

Reproductive suppression of females is found throughout the Callitrichids. However, in many species some evidence of ovarian activity is observed in subordinate females. Subordinate cotton-top tamarin females in our colony have never been observed to ovulate in the presence of a reproductive female. However, ovarian follicular development does occur, and measurable levels of urinary estrogen and luteinizing hormone are frequently found in subordinate females. We studied 11 female tamarins living in family groups with a reproductive female. Each of the 8 eldest daughters had measurable urinary estrogen and LH levels and showed a reduction of hormonal levels when new infants were born. The 3 younger daughters showed barely detectable hormonal levels that did not change. Following the birth of infants the eldest daughters scent marked less frequently, increased time in contact with and grooming group members other than the mother, but they were more often targets of aggression than immediately prior to infant births. The eldest daughters were somewhat less involved in care of new infants than expected, although they spent much time in proximity to those carrying the infants. These results suggest that the further reduction of hormonal levels in subordinate females after the birth of infants may function to prevent these females from competing with mothers during the post-partum estrus rather than recruiting the eldest daughters as helpers for infant care. [ABSTRACT FROM AUTHOR] more...

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. [ABSTRACT FROM AUTHOR] more...

We investigated the occurrence of rickets in adolescent tamarins (Saguinus imperator) residing at the Los Angeles Zoo. Compared to tamarins in the same colony without clinical evidence of bone disease (N = 6), rachitic platyrrhines (N = 3) had a decrease in their serum calcium concentration (P < .05). The affected tamarins also had lower serum 1,25-dihydroxyvitamin D3 (1,25-(OH) 2D3) levels than did non affected colony mates, but 2-10-fold higher concentrations than in Old World primates of a comparable developmental stage. New World primates in many different genera are known to exhibit target organ resistance to the active vitamin D3 metabolite, 1,25-(OH) 2D3, compensated by maintenance of high circulating concentrations of 1,25-(OH)2D3. The relatively low serum 1,25- (OH)2D3 concentration in rachitic tamarins and ultraviolet B radiation- deficient environment of these primates suggested that bone disease may be linked to a deficiency in the substrate for 1,25-(OH) 2D3, 25-hydroxyvitamin D3 (25-OHD3). Chronic exposure of platyrrhines in three different vitamin D resistant genera to an artificial UVB source resulted in 1) a significant increase in the mean serum 25-OHD3 (P < .001) and 1,25-(OH)2D3 (P < .02) Level over that encountered in platyrrhines not exposed to UVB; and 2) prevention of rachitic bone disease in irradiated individuals. These data further show that the serum 25-OHD3 and 1,25-0H2D3 levels are positively correlated in vitamin D-resistant platyrrhines (r = 0.64; P = .0014) and suggest that a compromise in cutaneous vitamin D3 production by means of UVB deprivation may limit necessary 1,25-(OH)2D3 production. [ABSTRACT FROM AUTHOR] more...

The Callitrichidae (marmosets and tamarins) typically give birth to twins, and infant care is shared by all group members. The potential benefits to callitrichids of having helpers were investigated in a study of 21 captive cotton-top tamarin (Saguinus oedipus) infants, living in groups with two to 12 older members. Time carried and suckled and amount of food received from other family members were recorded for each infant during the first 12 weeks of life. The results showed that infants in larger groups were carried more and received more food than those in smaller groups. Twin infants in larger families were less likely to be on the same carrier. Singleton infants were carried more than twins but did not receive more food. On average, individual caretakers in larger groups carried less and shared Less food with infants than those in smaller groups. When parental contributions to care were analyzed, no effects of group size were found on mothers' contributions to carrying or food sharing, but fathers in larger groups both carried infants Less and shared less food with them. There appear to be several benefits of a communal rearing system to cotton-top tamarins. 1) Infants may receive more care in larger families, thus in- creasing their chances of survival. 2) The burden of care is spread over several animals, reducing the costs to a given individual. 3) The parents, particularly fathers, may benefit most from reducing the costs of investing in the present litter and increasing their ability to invest in future litters. [ABSTRACT FROM AUTHOR] more...

This paper describes the development and validation of a plasma and urinary gonadotropin immunoassay for golden lion tamarins (Leontopithecus rosalia), an endangered New World callitrichid primate. The assay is derived from a macaque chorionic gonadotropin assay and was validated for both plasma and urine samples in L. rosalia. Levels of immunoreactive LH/CG in lion tamarin urine were highly correlated (r = + 0.98) with gonadotropin bioactivity. Immunoreactive LH/CG levels were examined in two contexts: in the urine of adult females and in the plasma of adult males after administration of estrogen. Peaks of gonadotropin excretion were detected in samples collected from nonpregnant adult females. The peaks occurred immediately prior to cyclic elevations in urinary estrogen excretion. Plasma LH/CG concentration in males measured 24 and 48 hours after a single 50 μg injection of estradiol benzoate were significantly lower than levels at these time points measured after control treatment. Together, the results of this study point to the utility of the gonadotropin assay for monitoring reproductive function in both female and male lion tamarins. [ABSTRACT FROM AUTHOR] more...

Little information has been published on the reproductive biology and behavior of the emperor tamarin (Saguinus imperator). We analyzed twelve years of data on emperor tamarins at the Los Angeles Zoo and made comparisons with data on cotton-top tamarins (Saguinus o. oedipus) and golden lion tamarins (Leontopithecus rosalia) from the same collection. Secondary sex ratios did not differ significantly from 50:50. Births were not strictly seasonal for any species. The number of infants reared had a significant effect on interbirth interval for all species, with shorter intervals when only one or no infants were reared, but females did sometimes conceive early in lactation. In emperor tamarin families, all fathers and most older siblings carried new infants, usually beginning within a few days after a birth. Previous exposure to younger siblings did not appear to be critical to the development of competent parental behavior by zooborn emperor tamarin females. [ABSTRACT FROM AUTHOR] more...

Captive colonies of cotton top tamarins experience a high rate of rejection of infants within the 1st week of life. The rates of rejection and survival to maturity (2 or more years) among 659 live colony-born infants were correlated with rearing, birth group, litter size, season of birth, gender, origin of parents, experience of parents raising siblings, parity and age of parents, and experience of parent pairs. The most important factors associated with low rejection rates were family life and parental experience raising infants. Infants born into family groups or reared in families were rejected at a significantly lower rate. Rejection of infants whose sires were raised with siblings was significantly lower. Paternal experience was more important than maternal experience. Litter size had no effect on rejection of infants born to family groups, whereas, rejection of triplets was significantly higher than twins or singles among those born to parents alone. Rejection was significantly higher among primiparous births than multiparous births. The combined experience of colony-born parents was not related to rejection if there were no sibling helpers in the cage at the time of birth. Rejection was significantly lower if sibling helpers were present. High survival of infants who were not rejected was correlated with rearing by or being born into family groups and higher parity and older age of the sires. [ABSTRACT FROM AUTHOR] more...