• Aspects of the behavioral and endocrine ontogeny of six moustached tamarins, Saguinus mystax (Callitrichinae)

      Huck, Maren; Löttker, Petra; Heymann, Eckhard W.; Heistermann, Michael; German Primate Centre (2004-12)
    • Demographic parameters and events in wild moustached tamarins (Saguinus mystax)

      Löttker, Petra; Huck, Maren; Heymann, Eckhard W.; German Primate Centre (2004-12)
      This paper examines demographic events in the context of population structure and genetic relationships in groups of wild moustached tamarins (Saguinus mystax). We used a combination of long-term behavioral observations and genetic data from a total of eight groups from a population in northeastern Peruvian Amazonia. The mean group size was 6.0 (range=4–9), including 2.5 adult males and 1.8 adult females. Within-group relatedness was generally high (r=0.3), and most nonbreeding individuals were either natal or closely related to the respective same-sex breeder. The mean annual persistence of adults in the groups was 70% and 68% for males and females, respectively, and the reproductive tenure of one breeding pair lasted for at least 6 years. Migrations predominantly occurred after stability-disrupting events such as the immigration of new individuals and/or the loss of breeding individuals, or when groups were rather large. Migrations of both breeding and nonbreeding males and females occurred. Our results show that the hypothesis of Ferrari and Lopes Ferrari [Folia Primatologica 52:132–147, 1989] that tamarins live in smaller and less stable groups with lower relatedness compared to marmosets does not generally hold true. In contrast, we found that tamarin groups can consist of predominantly related individuals, and are stable as well. It is also apparent that a single demographic event can produce a chain of subsequent complex demographic changes.
    • Endocrine correlates of reproductive status in breeding and nonbreeding wild female Moustached Tamarins

      Löttker, Petra; Huck, Maren; Heymann, Eckhard W.; Heistermann, Michael; Abteilung Soziobiologie, Deutsches Primatenzentrum, Göttingen, Germany; Institut für Neuro- und Verhaltensbiologie, Abteilung Verhaltensbiologie, Westfälische Wilhelms-Universität Münster, Germany; Lehrstuhl für Verhaltensforschung, Universität Bielefeld, Germany; Abteilung Reproduktionsbiologie, Deutsches Primatenzentrum Göttingen, Germany (2004-08)
      In callitrichid primates, reproduction is usually restricted to a single female per group. Reproductive rate is high and the occurrence of a postpartum estrus can lead to simultaneous lactation and pregnancy. In contrast, nonreproductive females often show ovarian inactivity. However, most studies on callitrichid reproductive physiology have been conducted in captivity, where conditions differ considerably from those in the wild, so that reproductive conditions may be strongly modified. Using fecal estrogen and progestogen measurements to monitor female reproductive status in 2 groups of wild moustached tamarins (Saguinus mystax), we examined 1) whether reproductive females in free-ranging groups also show postpartum estrus and 2) whether nonreproductive females demonstrate signs of ovarian activity. In both reproductive females, clear changes in the excretion pattern of progestogen and estrogen metabolites over time in combination with information on parturition dates allowed us to differentiate between pregnancy, a period of postpartum ovarian inactivity lasting for 54 and 64–82 days, and a period of ovarian activity before conception. Nonreproductive females demonstrated temporal fluctuations in hormone concentrations and absolute hormone levels that were similar to ones in the breeding females during the phase of ovarian activity. The results suggest that, in contrast to most captive female tamarins, reproductive females in wild groups of moustached tamarins do not have a postpartum estrus and that nonreproductive females show ovarian activity despite the presence of a breeding female.We therefore conclude that findings from captivity should be only carefully compared to the situation in the wild.
    • Grooming relationships between breeding females and adult group members in cooperatively breeding moustached tamarins (Saguinus mystax)

      Löttker, Petra; Huck, Maren; Zinner, Dietmar P.; Heymann, Eckhard W.; Department of Behavioral Ecology and Sociobiology, German Primate Centre; Department of Cognitive Ethology, German Primate Centre, Germany (2007)
      Grooming is the most common form of affiliative behavior in primates that apart from hygienic and hedonistic benefits offers important social benefits for the performing individuals. This study examined grooming behavior in a cooperatively breeding primate species, characterized by single female breeding per group, polyandrous matings, dizygotic twinning, delayed offspring dispersal, and intensive helping behavior. In this system, breeding females profit from the presence of helpers but also helpers profit from staying in a group and assisting in infant care due to the accumulation of direct and indirect fitness benefits. We examined grooming relationships of breeding females with three classes of partners (breeding males, potentially breeding males, (sub)adult non-breeding offspring) during three reproductive phases (post-partum ovarian inactivity, ovarian activity, pregnancy) in two groups of wild moustached tamarins (Saguinus mystax). We investigated whether grooming can be used to regulate group size by either ‘‘pay-for-help’’ or ‘‘pay-to-stay’’ mechanisms. Grooming of breeding females with breeding males and nonbreeding offspring was more intense and more balanced than with potentially breeding males, and most grooming occurred during the breeding females’ pregnancies. Grooming was skewed toward more investment by the breeding females with breeding males during the phases of ovarian activity, and with potentially breeding males during pregnancies. Our results suggest that grooming might be a mechanism used by female moustached tamarins to induce mate association with the breeding male, and to induce certain individuals to stay in the group and help with infant care.
    • Long-term patterns of sleeping site use in wild saddleback (Saguinus fuscicollis) and moustached tamarins (S. mystax): effects of foraging, thermoregulation, predation, and resource defense constraints

      Smith, Andrew C.; Knogge, Christoph; Huck, Maren; Löttker, Petra; Buchanan-Smith, Hannah M.; Heymann, Eckhard W.; German Primate Centre, Göttingen; University of Sussex; Anglia Ruskin University; Umweltforschungszentrum Leipzig-Halle; et al. (2007)
      Sleeping sites are an important aspect of an animal’s ecology given the length of time that they spend in them. The sleep ecology of wild saddleback and mustached tamarins is examined using a long-term data set covering three mixed-species troops and 1,3001 tamarin nights. Seasonal changes in photoperiod accounted for a significant amount of variation in sleeping site entry and exit times. Time of exit was more closely correlated with sunrise than time of entry was with sunset. Both species entered their sleeping sites when light levels were significantly higher than when they left them in the morning. Troops of both species used >80 individual sites, the majority being used once. Mustached tamarins never used the same site for more than two consecutive nights, but addlebacks reused the same site for up to four consecutive nights. mustached tamarins slept at significantly greater heights than saddleback tamarins. There were consistent interspecific differences in the types of sites used. Neither the presence of infants, season, nor rainfall affected the types or heights of sites chosen. Sleeping sites were located in the central area of exclusive use more often than expected, and their position with respect to fruiting trees indicated a strategy closer to that of a multiple central place forager than a central place forager. These findings are discussed in light of species ecology, with particular reference to predation risk, which is indicated as the major factor influencing the pattern of sleeping site use in these species.
    • The many faces of helping: possible costs and benefits of infant carrying and food transfer in wild moustached tamarins (Saguinus mystax)

      Löttker, Petra; Huck, Maren; Heymann, Eckhard W.; Abteilung Soziobiologie, Deutsches Primatenzentrum, Göttingen, Germany; Lehrstuhl für Verhaltensforschung, Universität Bielefeld, Germany; Institut für Neuro- & Verhaltensbiologie, Abt. Verhaltensbiologie, Westfälische Wilhelms-Universität Münster, Germany (2004-07-01)
      Various hypotheses about adaptive and non-adaptive mechanisms of non-parental infant care have been put forward for different taxa (Emlen et al., 1991). The Neotropical callitrichid primates are renowned for their cooperative care of the twin litters. None of the studies conducted in the wild included information on genetic relationships within groups. This, however, is indispensable to evaluate the relevance of competing hypotheses concerning direct or indirect fitness gains. We studied two groups of wild moustached tamarins with known genetic relationships over a one-year period to examine individual time-budgets and contributions to infant carrying and food-transfer. With these data we tested whether helping behaviour might be a non-adaptive trait and, if not, whether indirect benefits via kin-selection could be excluded as an evolutionary force maintaining it. Other hypotheses on direct fitness benefits were discussed as far as (anecdotal) data permitted. Changes in time-budgets suggest costs, thus clearly refuting hypotheses assuming non-adaptivity. High within-group relatedness suggests kin-selection to be one driving force of maintaining the trait. However, non-parental individuals may help despite low relatedness. Data were not sufficient to decide which possible direct benefits most likely play a role in inducing non-relatives to help. Yet, two (non-exclusive) explanations seem to be the most probable ones: The chance to inherit the main-breeding position, and a certain chance of own direct reproductive success (the latter only for male helpers) due to polyandrous mating by the female. Other adaptive mechanisms may enhance benefits but are unlikely to be major selective forces since fitness gains are presumably rather small or uncertain.
    • Paternity and kinship patterns in polyandrous moustached tamarins (Saguinus mystax)

      Huck, Maren; Löttker, Petra; Böhle, Uta-Regina; Heymann, Eckhard W.; Abteilung Soziobiologie, Deutsches Primatenzentrum, Göttingen, Germany; Abteilung für Verhaltensforschung, Universität Bielefeld, Germany; Institut für Neuro- & Verhaltensbiologie, Abt. Verhaltensbiologie, Westfälische Wilhelms-Universität Münster, Germany; Arbeitsgruppe Primatengenetik, Deutsches Primatenzentrum (DPZ), Göttingen, Germany (2005)
      We studied patterns of genetic relatedness and paternity in moustached tamarins, small Neotropical primates living in groups of 1–4 adult males and 1–4 adult females. Generally only one female per group breeds, mating with more than one male. Twin birth are the norm. In order to examine the genetic consequences of this mating pattern, DNA was extracted from fecal samples collected from two principal and six neighboring groups. DNA was characterized at twelve microsatellite loci (average: seven alleles/locus). We addressed the following questions: Do all adult males have mating access to the reproductive female of the group? How is paternity distributed across males in a group? Can polyandrous mating lead to multiple paternity? Are nonparental animals more closely related to the breeders than to the population mean? And, are mating partners unrelated? Breeding females mated with all nonrelated males. In at least one group the father of the older offspring did not sire the youngest infant although he was still resident in the group. We also found evidence for multiple paternity in a supposed twin pair. Yet, within each group the majority (67–100%) of infants had the same father, suggesting reproductive skew. Relatedness within groups was generally high (average R 0.31), although both nonrelated males and females occurred, i.e., immigrations of both sexes are possible. Mating partners were never found to be related, hence inbreeding seems to be uncommon. The results suggest that while the social mating system is polyandry, paternity is often monopolized by a single male per group.
    • Proximate mechanisms of reproductive monopolization in male moustached tamarins (Saguinus mystax)

      Huck, Maren; Löttker, Petra; Heymann, Eckhard W.; German Primate Centre (2004)
      In moustached tamarin (Saguinus mystax) groups, the single breeding female mates polyandrously with most or all nonrelated adult males. Nonetheless, paternity is monopolized in many groups by a single male. No evidence for male endocrine suppression has been found in this species. The proximate mechanisms of monopolization thus remain poorly understood. The aim of this study was to investigate the possible impact of agonistic interactions and mate-guarding on the monopolization of paternity in male moustached tamarins. Furthermore, we evaluated the likely costs of these behaviors, and whether olfactory cues might be used for its timing. We used behavioral data on proximity, agonistic interactions, time budgets, and scent-marking behavior to answer these questions. While direct agonistic competition does not play a prominent role, fertile females were consorted in some periods by one male, the sire of the previous and next litter. Consorting was instigated nearly exclusively by the male. It probably occurred during the female’s periods of highest fertility, and thus likely functions as mate-guarding. The timing of the consortship was probably guided by olfactory cues in the female’s scent marks. While we did not obtain direct evidence for energy costs in terms of increased energy expenditure or decreased food intake, we found that consorting males are more conspicuous and therefore may be more vulnerable to predators.