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We observed a zoo-housed group of cotton-top tamarins (Saguinus oedipus) before and after a bout of severe targeted aggression directed towards two of its members. The aggression was so severe and repeated that the zoo personnel was forced to remove the two victims and the main aggressor. In the tense period that preceded removal, the tamarins showed increased aggression, a steeper and linear dominance hierarchy, and reduced post-conflict reconciliation compared to the period following removal. In contrast, affiliative interactions such as grooming and peaceful food transfers did not differ in the two periods of observations. Patterns of reciprocity also remained stable. These results highlight the flexibility of tamarin social relationships and provide useful information for managing captive colonies and improving animal welfare. [ABSTRACT FROM AUTHOR]

Simple Summary: We investigated the social structure of two groups of cooperatively breeding cotton-top tamarins (Saguinus oedipus) before and after the birth of infants. The two groups had different sizes and age compositions: one being smaller and only having two adults, the breeding pair, and the other being bigger and having several non-reproductive adults. We investigated the group structure by observing grooming relationships, and we studied infant care by observing the time that group members spent carrying infants. The results showed that the group with non-reproductive adults showed a stable structure after the birth of the infants, while the smaller group showed changes in their structure. We also found no evidence of a relationship between the time spent carrying infants and group position. In conclusion, the presence of non-reproductive adults could be a determinant factor in maintaining group stability, although group members do not seem to improve their social position through infant carrying. Cotton-top tamarins (Saguinus oedipus) are characterized by a system of cooperative breeding where helpers, in addition to the reproductive pair, contribute to infant care. Grooming interactions between individuals play an important role in establishing social relationships, creating an interconnected social network in the group. We used social network analysis to investigate the social structure of two groups of cotton-top tamarins with different sizes and compositions and study whether they remain stable after the birth of new infants. We also investigated the possible correlation between the time spent carrying infants and an increase in the grooming centrality. We found that group A (n = 13) had a stable grooming network that showed consistent stability after the birth, although group B (n = 8 and no adult helpers) changed its grooming network and showed a lower density after the birth. Infant carrying was not correlated with increased grooming centrality after the birth. These findings highlight the usefulness of social network analysis in the study of group structure in cooperatively breeding primates and suggest that the birth of offspring has a greater impact on the stability of groups without adult helpers. [ABSTRACT FROM AUTHOR]

Cotton-top tamarins (Saguinus oedipus) are characterized by a system of cooperative breeding where helpers, in addition to the reproductive pair, contribute to infant care. Grooming interactions between individuals play an important role in establishing social relationships, creating an interconnected social network in the group. We used social network analysis to investigate the social structure of two groups of cotton-top tamarins with different sizes and compositions and study whether they remain stable after the birth of new infants. We also investigated the possible correlation between the time spent carrying infants and an increase in the grooming centrality. We found that group A (n = 13) had a stable grooming network that showed consistent stability after the birth, although group B (n = 8 and no adult helpers) changed its grooming network and showed a lower density after the birth. Infant carrying was not correlated with increased grooming centrality after the birth. These findings highlight the usefulness of social network analysis in the study of group structure in cooperatively breeding primates and suggest that the birth of offspring has a greater impact on the stability of groups without adult helpers.

Anthropogenic climate change (CC) is affecting a wide range of ecosystems and species, modifying current biodiversity patterns, and increasing the risk of extinction for many species. To address this threat, identifying, managing and protecting climate refugia has been suggested as an approach to incorporate CC into systematic conservation planning. In this study, we applied a detailed Ecological Niche Modeling (ENM) approach with the Maximum Entropy Algorithm to assess the potential effects of CC on the distribution of climatic suitability for Saguinus leucopus and Saguinus oedipus. These two species were investigated to identify climate refugia, and to assess the effectiveness of Protected Areas (PAs). Correlative models were generated with presence records, and bioclimatic variables describing recent (~ 2000) and future (~ 2050) climates, with data from two Global Circulation Models (GCMs) under two Representative Concentration Pathways (RCP), describing moderate (RCP 4.5) and extreme (RCP 8.5) climate change scenarios. For both species, moderate and extreme CC scenarios resulted in expansion of climatic suitability. Refugia models, through the overlapping of GCMs, indicated that 88% and 82% of the recent climate suitability may act as refugia for S. leucopus and S. oedipus. Greater variation was found coming from GCM selection than from RCPs. Regions of exposure to climatic novelties were identified for both species. Results suggest that climate refugia for these species are critically under-protected, as only 5.7% and 9.9% respectively, coincide with current PAs. Finally, PAs that are playing an important role in preserving climate refugia for these species are mentioned. [ABSTRACT FROM AUTHOR]

This observational study analyzes the social dynamic and agonistic behavior between the two youngest males in a captive troupe of cotton-top tamarins, Saguinus oedipus, found at the Central Florida Zoo and Botanical Gardens located in Sanford, Florida. The troupe consists of a breeding pair, two sets of twins, and a set of triplets--totaling nine individuals. The study focuses on the second-youngest and youngest males in the troupe and how they interact with each other. S. oedipus possess certain social and communication behaviors. The main behaviors observed in this study are vocalizations and movements indicating aggression between the two males. This study concludes the cause of aggression is due to competition and lack of space. The patterns of agonistic behavior indicate either the second youngest would be pushed out or the youngest would leave the troupe if in the wild. Being confined in a zoo enclosure makes the needed separation impossible. An additional enclosure is constructed during the study to lessen the already existing aggression. This measure works for a short time before hostile interactions increase in frequency again. [ABSTRACT FROM AUTHOR]

Abstract Four novel Gram-stain-positive, non spore forming and fructose-6-phosphate phosphoketolase-positive strains were isolated from the faeces of a cotton top tamarin (Saguinus oedipus) and an emperor tamarin (Saguinus imperator). Phylogenetic analyses based on 16S rRNA revealed that bifidobacterial strains TRE 1T exhibit close phylogenetic relatedness to Bifidobacterium catulorum DSM 103154 (96.0%) and Bifidobacterium tissieri DSM 100201 (96.0%); TRE DT and TRE HT were closely related to Bifidobacterium longum subsp. longum ATCC 15708T with similarity values of 97.4% and 97.5%, respectively; TRI 7T was closely related to Bifidobacterium tissieri DSM 100201 (96.0%). The Average Nucleotide Identity (ANI) and in silico DDH (isDDH) analysis with closest neighbour supported an independent phylogenetic position of all strains with values ranged from 74 to 85% for ANI and from 24 to 28% for isDDH. DNA base composition of the four strains was in the range of 58.3–63.5 mol% G + C. Based on the phylogenetic, genotypic and phenotypic data, the strains TRE 1T, TRE DT, TRE HT and TRI 7T clearly represent four novel taxa within the genus Bifidobacterium for which the names Bifidobacterium primatium sp. nov. (type strain TRE 1T = DSM 100687T = JCM 30945T), Bifidobacterium scaligerum sp. nov. (type strain TRE DT = DSM 103140T = JCM 31792T), Bifidobacterium felsineum sp. nov. (type strain TRE HT = DSM 103139T = JCM 31789T) and Bifidobacterium simiarum sp. nov. (type strain TRI 7T = DSM 103153T = JCM 31793) are proposed. [ABSTRACT FROM AUTHOR]

Background Due to a sporadic occurrence of Mycobacterium avium subsp. paratuberculosis ( MAP) in non-human primates ( NHP), the susceptibility of different NHP to MAP should be investigated. Methods Fecal and tissue samples (ileum, ileocecal lymph node, bone marrow) of 20 animals (seven species) were analyzed by IS900-based PCRs and sequenced. Samples of MAP PCR positive NHP were further cultivated. Results MAP DNA was detectable in two animals; the ileum of a cottontop tamarin and the bone marrow of a common marmoset. Cultivation of MAP failed. Sequence analysis revealed 100% homology to the MAP-K10 sequence. Pathohistological examinations offered no direct correlation to a MAP infection. Conclusions MAP was detected for the first time in a common marmoset. But as both NHP suffered from other diseases, an asymptomatic infection with MAP was assumed. The detection of MAP in the bone marrow might play a role in establishing latent paratuberculosis, as known from tuberculosis. [ABSTRACT FROM AUTHOR]

Forty-five microorganisms were isolated on bifidobacteria selective medium from one faecal sample of an adult subject of the cotton-top tamarin ( Saguinus oedipus L.). All isolates were Gram-positive, catalase-negative, anaerobic, fructose-6-phosphate phosphoketolase positive, and asporogenous rod-shaped bacteria. In this study, only eight out of the forty-five strains were characterized more deeply, whereas the others are still currently under investigation. They were grouped by BOX-PCR into three clusters: Cluster I (TRE 17 T , TRE 7, TRE 26, TRE 32, TRE 33, TRE I), Cluster II (TRE C T ), and Cluster III (TRE M T ). Comparative analysis of 16S rRNA gene sequences confirmed the results from the cluster analysis and revealed relatively low level similarities to each other (mean value 95%) and to members of the genus Bifidobacterium . All eight isolates showed the highest level of 16S rRNA gene sequence similarities with Bifidobacterium scardovii DSM 13734 T (mean value 96.6%). Multilocus sequence analysis (MLSA) of five housekeeping genes ( hsp60 , rpoB , clpC , dnaJ and dnaG ) supported their independent phylogenetic position to each other and to related species of Bifidobacterium . The G + C contents were 63.2%, 65.9% and 63.0% for Cluster I, Cluster II and Cluster III, respectively. Peptidoglycan types were A3α l -Lys– l -Thr– l -Ala, A4β l -Orn (Lys)– d -Ser– d -Glu and A3β l -Orn– l -Ser– l -Ala in Clusters I, II and III, respectively. Based on the data provided, each cluster represented a novel taxon for which the names Bifidobacterium aerophilum sp. nov. (TRE 17 T = DSM 100689 = JCM 30941; TRE 26 = DSM 100690 = JCM 30942), Bifidobacterium avesanii sp. nov. (TRE C T = DSM 100685 = JCM 30943) and Bifidobacterium ramosum sp. nov. (TRE M = DSM 100688 = JCM 30944) are proposed. [ABSTRACT FROM AUTHOR]

Early primate evolution is connected to the efficient exploitation of the terminal branch habitat. Mammals that forage in this habitat constantly encounter flexible thin branches that bend under the weight of the animals and thus form steeply inclined and declined supports. This study was aimed to gain insight into how cotton-top tamarins - a previously proposed modern analogue for a hypothetical stage in early primate evolution with prehensile autopodia - meet the specific functional demands when navigating thin, branch-like supports of different orientation. X-ray motion analysis was combined with synchronous single limb substrate reaction force measurements to discern limb mechanical adjustments. Previously reported gait parameter adjustments were confirmed for moderate support orientations, but on the steepest inclines and declines kinematic discontinuities were observed. These are interpreted to emphasize the functional roles of the forelimbs (net-braking role) and hind limbs (net-propulsive role) already established for level and moderately inclined supports. Tensile forces were exerted by the forelimbs on the steepest inclines and by the hind limbs on the steepest declines (head-first descents). Even though non-specialized small mammals have also been shown to successfully negotiate similar supports, prehensility offers advantages for foraging on thin, steeply inclined and declined terminal branches. Thus, the evolution of prehensile autopodia in small early primates likely has enhanced the exploitation of the terminal branch habitat. [ABSTRACT FROM AUTHOR]

Sex allocation theory has been a remarkably productive field in behavioral ecology with empirical evidence regularly supporting quantitative theoretical predictions. Across mammals in general and primates in particular, however, support for the various hypotheses has been more equivocal. Population-level sex ratio biases have often been interpreted as supportive, but evidence for small-scale facultative adjustment has rarely been found. The helper repayment (HR) also named the local resource enhancement (LRE) hypothesis predicts that, in cooperatively breeding species, mothers invest more in the sex which assists with rearing future offspring and that this bias will be more pronounced in mothers who require extra assistance (i.e., due to inexperience or a lack of available alloparents). We tested these hypotheses in captive cotton-top tamarins ( Saguinus oedipus) utilizing the international studbook and birth records obtained through a questionnaire from ISIS-registered institutions. Infant sex, litter size, mother's age, parity, and group composition (presence of nonreproductive subordinate males and females) were determined from these records. The HR hypothesis was supported over the entire population, which was significantly biased toward males (the 'helpful' sex). We found little support for helper repayment at the individual level, as primiparous females and those in groups without alloparents did not exhibit more extreme tendencies to produce male infants. Primiparous females were, however, more likely to produce singleton litters. Singleton births were more likely to be male, which suggests that there may be an interaction between litter size adjustment and sex allocation. This may be interpreted as supportive of the HR hypothesis, but alternative explanations at both the proximate and ultimate levels are possible. These possibilities warrant further consideration when attempting to understand the ambiguous results of primate sex ratio studies so far. [ABSTRACT FROM AUTHOR]

The aim of this investigation was to study the welfare of 3 captive groups of cotton-top tamarins housed in different zoological parks. Ethological observations were conducted during 1 year. In addition, fecal samples were collected and the concentrations of glucocorticoids, androgens, and progestogens were measured. Within each group, no significant differences in fecal cortisol concentrations were found between subjects. The fecal concentrations of testosterone and progesterone significantly differed depending on the sexes and ages of the tamarins. A significant association was found among hormone concentrations, exhibit dimensions, and group composition. A highly significant correlation was found between all hormones considered and the space available for each subject. Significant differences in behavioral patterns were observed among groups, including social–individual, affiliative–aggressive, and anogenital–suprapubic scent marking. Correlations between hormone measurements and behaviors were detected. In conclusion, this study confirmed the associations between some behaviors exhibited by these nonhuman primates and both cortisol and testosterone; these data also highlight the role played by progesterone in these behaviors. [ABSTRACT FROM AUTHOR]

There has been a recent resurgence of interest in New World monkeys within the biomedical research community, driven by both the sequencing of the common marmoset (Callithrix jacchus) genome and a growing demand for alternatives to Old World primates. New World monkeys offer attractive advantages over Old World species, including cheaper and simpler husbandry, while still maintaining a greater evolutionary proximity to humans compared with other animal models. Although numerous commonalities across primate species exist, there are also important genetic and reproductive differences that can and should play a critical role in selecting appropriate animal models. Common marmosets in particular have significantly reduced diversity at the major histocompatibility complex (MHC) loci and are born as hematopoietic chimeras. New World primates can make ideal translational models for research, but scientists must necessarily incorporate complete understandings of their genetic and phenotypic differences from humans and other model organisms. [ABSTRACT FROM AUTHOR]

The combination of loss of habitat, human population encroachment, and increased demand of select nonhuman primates for biomedical research has significantly affected populations. There remains a need for knowledge and expertise in understanding background findings as related to the age, source, strain, and disease status of nonhuman primates. In particular, for safety/biomedical studies, a broader understanding and documentation of lesions would help clarify background from drug-related findings. A workshop and a minisymposium on spontaneous lesions and diseases in nonhuman primates were sponsored by the concurrent Annual Meetings of the American College of Veterinary Pathologists and the American Society for Veterinary Clinical Pathology held December 3–4, 2011, in Nashville, Tennessee. The first session had presentations from Drs Lowenstine and Montali, pathologists with extensive experience in wild and zoo populations of nonhuman primates, which was followed by presentations of 20 unique case reports of rare or newly observed spontaneous lesions in nonhuman primates (see online files for access to digital whole-slide images corresponding to each case report at http://www.scanscope.com/ACVP%20Slide%20Seminars/2011/Primate%20Pathology/view.apml). The minisymposium was composed of 5 nonhuman-primate researchers (Drs Bradley, Cline, Sasseville, Miller, Hutto) who concentrated on background and spontaneous lesions in nonhuman primates used in drug safety studies. Cynomolgus and rhesus macaques were emphasized, with some material presented on common marmosets. Congenital, acquired, inflammatory, and neoplastic changes were highlighed with a focus on clinical, macroscopic, and histopathologic findings that could confound the interpretation of drug safety studies. [ABSTRACT FROM PUBLISHER]

The social factors that influence cooperation have remained largely uninvestigated but have the potential to explain much of the variation in cooperative behavior observed in the natural world. We show here that certain dimensions of the social environment, namely the size of the social group, the degree of social tolerance expressed, the structure of the dominance hierarchy, and the patterns of dispersal, may influence the emergence and stability of cooperation in predictable ways. Furthermore, the social environment experienced by a species over evolutionary time will have shaped their cognition to provide certain strengths and strategies that are beneficial in their species' social world. These cognitive adaptations will in turn impact the likelihood of cooperating in a given social environment. Experiments with one primate species, the cottontop tamarin, illustrate how social dynamics may influence emergence and stability of cooperative behavior in this species. We then take a more general viewpoint and argue that the hypotheses presented here require further experimental work and the addition of quantitative modeling to obtain a better understanding of how social dynamics influence the emergence and stability of cooperative behavior in complex systems. We conclude by pointing out subsequent specific directions for models and experiments that will allow relevant advances in the understanding of the emergence of cooperation. [ABSTRACT FROM AUTHOR]

Infant carrying is common in primates and may be the second most costly activity related to reproduction, after lactation. In cooperative breeding groups of callitrichids, all group members carry and care for twin infants. Previous studies have described the costs of infant carrying in terms of body mass loss and reduced locomotor capability. However, infant carrying may also influence travel speed, an important potential cost because slower speed may handicap foraging, energetic budgets, and predator avoidance. We evaluated the impact of infant carrying on the travel speed of 27 adult and 9 subadult cotton-top tamarins ( Saguinus oedipus) of both sexes in large outdoor enclosures. We compared carrier speed to speed when not carrying during the 10 weeks after nine births. Subadult tamarins, which have a lower body mass than adults do, moved faster than adults when not carrying. We found no difference between the mean speeds of subadults and adults while carrying. However, the speed of carriers decreased as infant mass increased, and the slope of this negative relationship was more pronounced in subadult carriers. For every 80 g of extra mass load (the body mass of newborn twins), adults reduced their speed by 6 % and subadults by 19 % relative to noncarrying speed. We also observed a reduction in speed while carrying two infants in adult tamarins as carrying time increased. Our results contribute to an understanding of the costs of infant carrying, and serve to emphasize the importance of cooperative breeding systems in coping with these costs. [ABSTRACT FROM AUTHOR]

The article features a study that investigates the novel adenovirus of platyrrhine primates in Florida. Researchers examined seven-year-old tamarin with gastrointestinal and respiratory illness using the electron microscopy and nested polymerase chain reaction (nPCR). Moreover, they found that there is direct correlation of the virus and the diarrhea of the tamarin.

In the biparental, cooperatively breeding cottontop tamarin, Saguinus oedipus oedipus, adult sons provide an energetically and reproductively valuable service to their breeding parents by helping to carry infants. Other species may use aggressive coercion or punishment to enforce alloparenting. Yet, affiliation in primates is important in negotiating social relationships and may be exchanged for services. We hypothesized that the rewards of grooming might be used by expectant parents to cultivate strong relationships with and maintain the services of adult son alloparents. We tested for an interchange trade of aggression or grooming for infant carrying according to a biological market. Individual rates of grooming, but not aggression, received by sons were explained by previously demonstrated levels of alloparental infant carrying. However, the direction of the interaction differed according to the sex of the parent. Mothers groomed better carriers at a higher rate, whereas fathers groomed poorer carriers at a higher rate. This sex difference in parental behaviour may reflect differential benefits that male and female breeders receive with increasing help. Market predictions based on alloparent availability were not supported, but results indicated a connection between affiliation and cooperative service. The rates of huddling and contact affiliation between fathers and adult sons suggest a sex-specific set of social relationship traits conducive to both affiliation and infant carrying. These may be necessarily tied to the particular form of infant care by males in this cooperatively breeding species. Fathers may condition sons for the social aspects of carrying, which involve socially coordinated efforts and close physical proximity between adult males. [Copyright &y& Elsevier]

The crouched limb posture of small mammals enables them to react to unexpected irregularities in the support. Small arboreal primates would benefit from these kinematics in their arboreal habitat but it has been demonstrated that primates display certain differences in forelimb kinematics to other mammals. The objective of this paper is to find out whether these changes in forelimb kinematics are related to changes in body size and limb proportions. As primates descended from small ancestors, a comparison between living small primates and other small mammals makes it possible to determine the polarity of character transformations for kinematic and morphometric features proposed to be unique to primates. Walking kinematics of mouse lemurs, brown lemurs, cotton-top tamarins and squirrel monkeys was investigated using cineradiography. Morphometry was conducted on a sample of 110 mammals comprising of primates, marsupials, rodents and carnivores. It has been shown that forelimb kinematics change with increasing body size in such a way that limb protraction increases but retraction decreases. Total forelimb excursion, therefore, is almost independent of body size. Kinematic changes are linked to changes in forelimb proportions towards greater asymmetry between scapula and radius. Due to the spatial restriction inherent in the diagonal footfall sequence of primates, forelimb excursion is influenced by the excursion of the elongated hind limb. Hindlimb geometry, however, is highly conserved, as has been previously shown. The initial changes in forelimb kinematics might, therefore, be explained as solutions to a constraint rather than as adaptations to the particular demands of arboreal locomotion. [ABSTRACT FROM PUBLISHER]

To maximize transmission in noisy environments, vocalizing animals have evolved capacities to avoid the masking effects of biotic and abiotic sound sources, such as changing the structure and timing of acoustic signals. Here we explore this problem from a new angle, asking whether animals can extract predictive acoustic cues from an intermittently noisy environment and use this information to guide the timing of their vocalizations. In a series of experiments, we presented cottontop tamarins, Saguinus oedipus, with loud noise interrupted by speech syllables and silence. The silences were either long enough to accommodate the full length of their species-specific contact calls or too short. The task, in brief, was for tamarins to pick out the acoustic cues predicting long versus short gaps of silence, and to time their vocalizations to follow cues associated with long gaps. Consistently, and across all subjects tested, tamarins were able to extract the acoustic cues predicting the long gaps, using them to call in the long gaps and consequently, avoiding both the energetic and masking costs of calling in noise. We discuss these findings and the potential applications of this technique to broader questions of pattern recognition and the flexible use of vocal signals in a noisy environment. [Copyright &y& Elsevier]

Our longitudinal study explored the role of socially biased learning in the acquisition of a novel foraging task that could be solved in two ways in captive juvenile cottontop tamarins. We trained parents to adopt a single solution (pole or ceiling strategy). We tested 13 different juvenile offspring–parent pairs on the task over the course of 11 weeks. Our objective was (1) to investigate the extent to which juveniles match their parent, and (2) to analyse the influence of behavioural feedback between parent and juvenile offspring on learning trajectories, behavioural acquisition and performance. Although not all juveniles matched the modelled solution, both groups of juveniles significantly spent more time at the targeted location being modelled for them. Parent and offspring correlated well in time spent at the demonstrated location. We investigated predictors of performance and success by analysing data prior to first success. Juveniles'' exploration of the apparatus was important in dictating their success at the task, whereas observation of the parent had no influence. Both juvenile scrounging and adult food calling, which encouraged begging, drew the attention of the juveniles away from the task and impeded learning. High adult refusals per beg predicted task success in young. Adults monitored their offspring''s performance and increased their refusals per begs upon the first success of their offspring. Cottontop tamarins also showed some behavioural scaffolding. Solving the task did not simply reflect a maturational change in juveniles, but was rather influenced by an intricate behavioural feedback between parent and offspring. [Copyright &y& Elsevier]

Cooperation among nonhuman animals has been the topic of much theoretical and empirical research, but few studies have examined systematically the effects of various reward payoffs on cooperative behaviour. Here, we presented heterosexual pairs of cooperatively breeding cottontop tamarins with a cooperative problem-solving task. In a series of four experiments, we examined how the tamarins'' cooperative performance changed under conditions in which (1) both actors were mutually rewarded, (2) both actors were rewarded reciprocally across days, (3) both actors competed for a monopolizable reward and (4) one actor repeatedly delivered a single reward to the other actor. The tamarins showed sensitivity to the reward structure, showing the greatest percentage of trials solved and shortest latency to solve the task in the mutual reward experiment and the lowest percentage of trials solved and longest latency to solve the task in the experiment in which one actor was repeatedly rewarded. However, even in the experiment in which the fewest trials were solved, the tamarins still solved 46±12% of trials and little to no aggression was observed among partners following inequitable reward distributions. The tamarins did, however, show selfish motivation in each of the experiments. Nevertheless, in all experiments, unrewarded individuals continued to cooperate and procure rewards for their social partners. [Copyright &y& Elsevier]

We investigated the development of food transfer and independent feeding in cotton-top tamarin (Saguinus oedipus) families. We studied the relationship between infant-directed vocalizations and food transfers on the development of independent feeding in infants. We experimentally tested ten infants (eight twins and two singletons) three times a week for 17 weeks from before weaning through 20 weeks. Food transfers and vocalizations made during tests were recorded and analyzed to determine (1) the role of vocalizations (C- and D- chirps and D-chirp series) in food acquisition, (2) the relationship between food transfers and individual food acquisition, and (3) whether, owing to energetic costs of nursing and carrying twins, food is transferred to twins sooner than to singletons. Infants were more successful in acquiring food via begging when adults produced repeated vocalizations than when adults did not vocalize. Adults emitted more food-related vocalizations in rapid series when in the presence of infants, whereas during feeding in the absence of infants only single unit vocalizations were produced. Begging occurred frequently. Changes over infant age were not significant when all infants were included in analysis. However, when twin data were analyzed alone, begging success changed significantly over months, with successful begging peaking in month 3 (week 12). Begging success rate did not differ between twins and singletons, although twins fed independently sooner and at a higher rate than did singletons. Am. J. Primatol. 69:955–965, 2007. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Muscle fiber type composition of intrinsic shoulder muscles was examined in tree shrews, cotton-top tamarins, and squirrel monkeys with respect to their shoulder kinematics and forelimb loading during locomotion. Enzyme- and immunohistochemical techniques were applied to differentiate muscle fiber types on serial cross-sections of the shoulder. In the majority of the shoulder muscles, the proportions of fatigue resistant slow-twitch fibers (SO) and fatigable fast-twitch fibers (FG) were inversely related to each other, whereas the percentage of intermediate FOG-fibers varied independently. A segregation of fatigue resistant SO-fibers into deep muscle regions is indicative of differential activation of histochemically distinct muscle regions in which deep regions stabilize the joint against gravitational loading. In all three species, this antigravity function was demonstrated for both the supraspinatus and the cranial subscapularis muscle, which prevent passive joint flexion during the support phase of the limb. The infraspinatus muscle showed a high content of SO-fibers in the primate species but not in the tree shrew, which demonstrates the “new” role of the infraspinatus muscle in joint stabilization related to the higher degree of humeral protraction in primates. In the tree shrew and the cotton-top tamarin, a greater proportion of the body weight is carried on the forelimb, but the squirrel monkey exhibits a weight shift to the hind limbs. The lower amount of forelimb loading is reflected by an overall lower proportion of fatigue resistant muscle fibers in the shoulder muscles of the squirrel monkey. Several muscles such as the deltoid no longer function as joint stabilizers and allow the humerus to move beyond the scapular plane. These differences among species demonstrate the high plasticity of the internal muscle architecture and physiology which is suggested to be the underlying reason for different muscle activity patterns in homologous muscles. Implications for the evolution of new locomotor modes in primates are discussed. [Copyright &y& Elsevier]

Abstract: Sleep quantitation data on the Neotropical primate species, apart from the squirrel monkey, are still sparse. As such, we have quantitated sleep in the common marmosets (Callithrix jacchus), cotton top tamarins (Saguinus oedipus) and squirrel monkeys (Saimiri sciureus) reared in one primate facility simultaneously, by non-invasive actigraphy. The range in total sleep time/24h measured for male adult common marmosets, cotton top tamarins and squirrel monkeys were 713–793min (n =4), 707–889min (n =4) and 459–475min (n =2) respectively. The range in sleep episode length /12h dark phase for marmosets, tamarins and squirrel monkeys were 21–52min (n =3), 10–28min (n =4) and 9–15min (n =2) respectively. Since vigilance is a critical evolutionary adaptive feature of predator avoidance among Callitrichid monkeys and squirrel monkeys, the shorter ranges in sleep episode length recorded, even under captivity, in this study could be interpreted as probable indicators of such vigilance behavior during the rest phase. We hypothesize that the vigilance behavior when it exists during a primate''s active phase should also prevail when it is at rest (sleep). This hypothesis deserves additional testing in female Callitrichid monkeys. [Copyright &y& Elsevier]

Similar in body size, locomotor behaviour and morphology to the last common ancestor of Primates, living small quadrupedal primates provide a convenient model for investigating the evolution of primate locomotion. In this study, the hind limb kinematics of quadrupedal walking in mouse lemurs, brown lemurs, cotton-top tamarins and squirrel monkeys are analysed using cineradiography. The scaling of hind limb length to body size and the intralimb proportions of the three-segmented hind limb are taken into consideration when kinematic similarities and differences are discussed. Hind limb kinematics of arboreal quadrupedal primates, ranging in size between 100 g and 3000 g, are size independent and resemble the hind limb kinematics of small non-cursorial mammals. A common feature seen in smaller mammals, in general, is the horizontal position of the thigh at touchdown and of the lower leg at lift-off. Thus, the maximum bone length is immediately transferred into the step length. The vertical position of the leg at the beginning of a step cycle and of the thigh at lift-off contributes the same distance to pivot height. Step length and pivot height increase proportionally with hind limb length, because intralimb proportions of the hind limb remain fairly constant. Therefore, the strong positive allometric scaling of the hind limb in arboreal quadrupedal primates affects neither the kinematics of hind limb segments nor the total angular excursion of the limb. The angular excursion of the hind limb in quadrupedal primates is equal to that of other non-cursorial mammals. Hence, hind limb excursion in larger cercopithecine primates differs from that of other large mammals due to the decreasing angular excursion as part of convergent cursorial adaptations in several phylogenetic lineages of mammals. Typical members of those phylogenetic groups are traditionally used in comparison with typical primates, and therefore the ‘uniqueness’ of primate locomotor characteristics is often overrated. [ABSTRACT FROM AUTHOR]

Infant carrying in cotton-top tamarins is a costly activity that results in weight loss by the fathers and helpers. However, to date, measures of carrying costs have been obtained in small indoor enclosures. We studied body weight changes in adult and subadult individuals from eight large groups (n>5) for 9 weeks after the birth of infants. Four groups were housed in large indoor/outdoor enclosures (42 m2×3.3 m high), and four were housed in small indoor enclosures (12 m2×2.4 m high). All of the individuals were weighed regularly at least three times a week. Reproductive males lost more weight in the big indoor/outdoor enclosures (mean=6.51%) than in the small indoor ones, as did male adult helpers (mean=5.59%) and female adult helpers (mean=4.4%). Still-growing subadult individuals also lost weight in the big indoor/outdoor enclosures (mean=3.17%), although the differences did not reach significance (P=0.07). These results support the hypothesis that cotton-top tamarins living in more natural settings experience higher weight loss than those housed under less-natural conditions. Am. J. Primatol. 66:279–284, 2005. © 2005 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The cell line B95-8 releases Epstein–Barr virus (EBV) with high titres of transforming activity and is widely used as a model in cancer research and virology. There are, however, controversial reports about the species of origin, cell line stability and karyotype. To address these questions, B95-8 chromosomes were analysed by chromosome sorting and painting by multicolour fluorescence in-situ hybridization. Reciprocal painting was performed between B95-8, ‘wildtype’ New World monkey and human chromosomes. Saguinus oedipus was revealed as the species of origin. A further five cell-line-specific marker chromosomes, resulting from translocations, deletions and an insertion were found. Although human chromosome 6 or 13 homologues were always involved in these rearrangements, co-hybridization of an EBV-specific DNA probe did not reveal site-specific hybridization to marker chromosomes or at translocation breakpoints. The multicolour probe set described here will be of special value for further evolutionary studies in New World monkeys. [ABSTRACT FROM AUTHOR]

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]

When mature female cotton-top tamarins are removed from the reproductive suppression of their mother, reproductive hormone levels and scent-marking behaviour increase, but the females do not ovulate until paired with an unfamiliar male. This study determined the effects of exposure to male urine and direct contact with both familiar and unfamiliar males on sociosexual behaviour and urinary oestrone and gonadotropin secretion in pubertal females. Seven females were observed when they resided with family members, in isolation, and after pairing with an unfamiliar male. Initially, the females were housed either in their natal group or with a familiar male(s) only. When housed in isolation, the females were exposed daily to either male urine or water. Neither urinary hormone levels nor sociosexual behaviour differed between females housed with their natal group and those housed only with familiar males. In isolation, urinary oestrone and scent marking increased, but hormonal excretion was acyclic; daily exposure to male urine did not influence hormones or behaviour. Sexual behaviour was almost never observed when females lived with family members but increased significantly after pairing. One female began ovulatory cycling in the presence of a familiar male, no female began cycling in isolation, and five females began cycling after pairing. The results from this and previous studies indicate that the onset of sexual behaviour and ovarian cyclicity may require not only release from suppression by the mother but also release from suppression by other family members as well as direct contact or stimulation from an unfamiliar male. The combination of suppressive and stimulatory factors may serve as mechanisms for avoidance of inbreeding and to promote group dispersal.

Marmosets and tamarins have a communal rearing system in which all group members help to care for the twin infants characteristic of this family of primates. Helpers are likely to incur time and energy costs by contributing to infant care. Predictions that cotton-top tamarin (Saguinus oedipus) helpers would change their behavior when carrying infants because of reduced mobility and/or a need for increased vigilance were tested in a captive colony. Tamarins carrying an infant spent significantly less time feeding, foraging, moving, or engaging in social activities such as grooming than they did when not carrying. Frequencies of scratching, autogrooming, and scent marking were significantly reduced in carriers, suggesting that their mobility was reduced. However, carriers were significantly less likely to be vigilant (measured by direction of gaze) than when not carrying. Further observations showed that carriers spent more time in concealed areas than they did when not carrying and were probably therefore adopting a cryptic strategy to reduce predation risks to themselves and to infants. These results demonstrate that tamarin helpers pay costs by carrying infants. Some possible compensating benefits are indicated. [ABSTRACT FROM AUTHOR]