Leontopithecus Chrysomelas Research Articles

An Evaluation of the Suitability of Contraceptive Methods in Golden-Headed Lion Tamarins(Leontopithecus Chrysomelas), with Emphasis on Melengestrol Acetate (MGA) Implants: (II) Endocrinological and Behavioural Effects

AbstractIn order to be suitable, a contraceptive method should have little or no effects on social organization or behaviour. In callitrichids, changes in socio-sexual interactions between group members, due to hormonal changes induced by contraception, may have consequences for the reproductive inhibition of offspring in their natal group. This may lead to an increased rate of inbreeding. In this paper we report on the endocrinological and behavioural effects of contraception in golden-headed lion tamarins, using data obtained through a world survey and an observational study. Hormonal analysis of urinary oestrone conjugate levels in melengestrol acetate (MGA)-implanted females confirmed earlier preliminary findings (Van Elsackeret al1994): MGA implants inhibited reproduction through the suppression of ovulation and regular ovarian cycles in the implanted female, while the occurrence of ovarian cycles in the oldest female offspring of each group was not affected. Sexual interactions between the dominant adults still occurred but underwent temporal changes. Reproductive inhibition in female offspring was maintained. Social interactions between group members altered in a non-consistent way but did not have an impact on the stability of the study groups during the study. In principle, MGA implants do not have a detrimental impact on the behaviour of group members. The suitability of MGA implants from a behavioural point of view depends on the extent to which those involved wish to preserve the entire range of natural behaviours for this species. The behavioural effects of other contraceptive methods are still largely unknown.

An Evaluation of the Suitability of Contraceptive Methods in Golden-Headed Lion Tamarins (Leontopithecus Chrysomelas), with Emphasis on Melengestrol Acetate (MGA) Implants: (I) Effectiveness, Reversibility and Medical Side-Effects

AbstractFinding a responsible method of population control that does not compromise animal welfare is a pressing problem for zoological institutions and conservation breeding programmes. This is exemplified by the conservation breeding programme of the golden-headed lion tamarin,Leontopithecus chrysomelas. The number of golden-headed lion tamarins in captivity is currently being limited by, among other means, the use of contraception. We have conducted a study on the effects of contraceptive methods used in golden-headed lion tamarins. Data were collected through the distribution of a survey. The use of Melengestrol acetate (MGA) implants in females was by far the most widespread contraceptive method. It was very effective in preventing reproduction, provided that females were not pregnant at the time of implantation. Pregnancies that had commenced before MGA implantation were carried to term and resulted in viable infants, as far as noted. However, the degree of reversibility was very low and, if females did conceive after MGA implantation, infant survival was lower than expected. The widespread use of MGA implants in golden-headed lion tamarins (and probably other species) should be seriously reconsidered. Alternative methods of population control should be investigated. Possible options include the use of other contraceptive methods, limiting the number of offspring through natural factors and the use of euthanasia under very strict conditions. Animal welfare implications associated with the use of euthanasia are discussed.

Signaling of Reproductive Status in Captive Female Golden-Headed Lion Tamarins (Leontopithecus chrysomelas)

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.

Cross-generic Food Sharing in Tamarins

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.

Aggressive response toward intruders by captive male <i>Leontopithecus chrysomelas</i>

No abstract

Geographic Distribution of the Golden-Headed Lion Tamarin, Leontopithecus chrysomelas: Implications for Its Management and Conservation

The geographic distribution and conservation status of the golden-headed lion tamarin, Leontopithecus chrysomelas, were studied during a survey carried out through an area of about 37,000 km2 in southern Bahia from March 1991 to March 1993. The survey involved interviews of local people and direct censusing in 33 forest patches using playback recordings of a male and female lion tamarin long-call. Populations were found to occur in 94 localities. An Appendix provides a full gazetteer of these localities and a further 28 localities recorded in previous studies. The distributional limits were found to agree closely with the ranges described by previous authors, except for its absence in the extreme north-east of its range, from the south of the Rio de Contas to the Rio Almada, where it might have become extinct. The total geographic range was estimated to cover approximately 19,462 km2, including two distinct regions in terms of land use and forest cover. The forests in both regions are severely reduced and fragmented. Unlike the other three species of lion tamarins, L. chrysomelas evidently still occurs throughout a large part of its historic range, but the fragmentation and rapid rate of forest destruction clearly indicate that the species is endangered. The Una Biological Reserve is the only protected area within its range, and is believed to be too small (7,059 ha) to maintain a genetically viable population. The conservation status of L. chrysomelas is discussed, particularly in terms of the socioeconomy of the region where it occurs, as well as the need for further ecological research.

Chromosomal similarities and differences between tamarins, Leontopithecus and Saguinus (Platyrrhini, Primates).

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.

Reproduction in captive lion tamarins (Leontopithecus): Seasonality, infant survival, and sex ratios

Diversity in reproductive and social systems characterizes the primate family Callitrichidae. This paper contributes to our appreciation of this diversity by presenting the first detailed comparative analysis of captive breeding in three species of lion tamarins (Leontopithecus chrysomelas, L. chrysopygus, and L. rosalia) housed at the Centro de Primatologia do Rio de Janeiro. The annual pattern of reproduction in all three species of Leontopithecus was markedly seasonal, with births occurring during the spring, summer, and fall months from August through March. While modal number of litters produced per female per year was 1, approximately 20% of breeding females produced two litters per year. The onset of breeding activity in years when two litters are produced was significantly earlier than in years when only one litter was produced. The cumulative number of offspring surviving to 3 months of age did not differ between years with one vs. two breeding attempts. Like other callitrichids, postnatal mortality was highest during the first week of life, and there were pronounced species differences in offspring survival through 1 year, with significantly lower survivorship in L. chrysomelas. Infant survivorship was affected by a number of experiential factors. Survivorship up to 30 days of life was higher in groups in which the breeding female had previous experience with infants as a nonbreeding helper than in groups in which the female lacked previous helping experience. Likewise, survivorship to 30 days of life was higher for infants born to multiparous females than for infants born to primiparous females. When parity and previous helping experience were analyzed concurrently, the lowest survivorship was associated with offspring produced by inexperienced primiparous females. Genus-wide, there was no significant departure from a 50:50 sex ratio at any point during the first year of life, nor was there evidence for differential mortality for male and female infants. However, L. chrysopygus produced significantly more male infants at birth (65:44) and had male-biased litters (approximately 60% males) throughout the first year of life, while L. chrysomelas showed a nonsignificant tendency toward female-biased litters. © 1996 Wiley-Liss, Inc.

Reproduction in captive lion tamarins (Leontopithecus): Seasonality, infant survival, and sex ratios.

Diversity in reproductive and social systems characterizes the primate family Callitrichidae. This paper contributes to our appreciation of this diversity by presenting the first detailed comparative analysis of captive breeding in three species of lion tamarins (Leontopithecus chrysomelas, L. chrysopygus, and L. rosalia) housed at the Centro de Primatologia do Rio de Janeiro. The annual pattern of reproduction in all three species of Leontopithecus was markedly seasonal, with births occurring during the spring, summer, and fall months from August through March. While modal number of litters produced per female per year was 1, approximately 20% of breeding females produced two litters per year. The onset of breeding activity in years when two litters are produced was significantly earlier than in years when only one litter was produced. The cumulative number of offspring surviving to 3 months of age did not differ between years with one vs. two breeding attempts. Like other callitrichids, postnatal mortality was highest during the first week of life, and there were pronounced species differences in offspring survival through 1 year, with significantly lower survivorship in L. chrysomelas. Infant survivorship was affected by a number of experiential factors. Survivorship up to 30 days of life was higher in groups in which the breeding female had previous experience with infants as a nonbreeding helper than in groups in which the female lacked previous helping experience. Likewise, survivorship to 30 days of life was higher for infants born to multiparous females than for infants born to primiparous females. When parity and previous helping experience were analyzed concurrently, the lowest survivorship was associated with offspring produced by inexperienced primiparous females. Genus-wide, there was no significant departure from a 50:50 sex ratio at any point during the first year of life, nor was there evidence for differential mortality for male and female infants. However, L. chrysopygus produced significantly more male infants at birth (65:44) and had male-biased litters (approximately 60% males) throughout the first year of life, while L. chrysomelas showed a nonsignificant tendency toward female-biased litters. © 1996 Wiley-Liss, Inc.

Research on golden-headed tamarins at Antwerp zoo

No abstract

Long-call structure and its relation to taxonomy in lion tamarins.

Recent evidence on craniodental morphology suggests the acceptance of three species of lion tamarins (Leontopithecus). Confirmatory evidence is presented here using the morphology of long-call vocalizations recorded from several individuals of each type of lion tamarin. Recordings were made of Leontopicthecus rosalia, Leontopithecus chrysopygus, and Leontopithecus chrysomelas at the Centro de Primatologia do Rio de Janeiro (FEEMA) and of L. rosalia at Monkey Jungle in Florida. Thirty separate parameters were measured, and 17 of them differed significantly between populations. In general, L. chrysomelas had higher pitched calls with shorter note duration, while L. chrysopygus, the larger of the animals, had lower pitched calls with longer note duration. L. rosalia was either intermediate to the other two populations or resembled L. chrysopygus. Thus, the results from the analysis of vocal structures closely paralleled the results obtained with more traditional taxonomic methods and suggests that the quantitative analysis of vocal strucures can be a useful adjunct in taxonomy.

Morphology, Taxonomic Status and Affinities of the Lion Tamarins, Leontopithecus (Callitrichinae, Cebidae)

A survey of craniodental variability of the three allopatric populations of Leontopithecus reveals that they are morphologically heterogeneous and individually distinctive, with a nonclinal distribution of characters and pattern similarities. These observations correspond with their better known, starkly different coat coloration, and imply important ecological-adaptive differences. Leontopithecus chrysomelas contrasts markedly in its robust physique, relatively massive and anatomically modified incisors, comparatively small cheek teeth and unique cranial shape. Leontopithecus rosalia is smallest and most gracile, with a highly abbreviated premaxilla and reduced anterior dentition. Leontopithecus chrysopygus is quite the largest in most bodily and cranial dimensions yet is more similar to Leontopithecus rosalia in anterior tooth size and proportions, and has a massively built face. Phyletically, Leontopithecus is most closely related to Callithrix (incl. Cebuella) among the callitrichines. Protection of their habitats is urged for there are three times as many species of endangered Lion Tamarins as we had thought.