Andrew J. Baker

Effects of Allocare-Givers on Fitness of Infants and Parents in Callitrichid Primates

The effects of callitrichid primate helpers (allocare-givers other than an infant’s father) on the survival, reproduction or behavior of infants and parents are reviewed, using both published studies and data from free-ranging golden lion tamarins (Leontopithecus rosalia). Three lines of evidence suggest that helpers may increase their own inclusive fitness: (1) The number of adult males acting as helpers in free-ranging groups is correlated with the number of surviving infants in 3 callitrichid species. However, the lack of a negative correlation with number of infants dying suggests that activities other than direct infant care (e.g. territory defense) may be more important, especially in newly formed groups. (2) In 2 species, captive groups with helpers carry infants for longer periods of time than do groups without helpers. Whether such differences would translate into meaningful survival differences in free-ranging groups is unclear. (3) Helpers reduce the energetic burden of parents by reducing the amount of time they spend transporting or provisioning infants in at least 4 species. Reproductive males are more likely than reproductive females to benefit from the presence of helpers, reducing their investment in infant care activities as the number of helpers in the group increases. In free-ranging golden lion tamarins, the reproductive tenure of males, but not females, increases with the number of helpers in the group, suggesting that a reduction in energetic investment may translate into increased survival. ‘Decisions’ made by helpers to participate in infant transport are weighed against competing needs for foraging, vigilance, territory defense and, in some cases, prospecting for breeding opportunities. Given this complexity, a sophisticated model may be required to answer the question of how helpers ‘decide’ to participate in infant care versus other activities.

Trypanosoma cruzi infection in Leontopithecus rosalia at the Reserva Biológica de Poço das Antas, Rio de Janeiro, Brazil

Wild golden lion tamarins (Leontopithecus rosalia) - endangered primates that are native to the Brazilian Atlantic coastal forest - were surveyed for the presence of Trypanosoma cruzi with the use of Giemsa-stained blood smears, hemocultures and an indirect immunofluorescence assay (IFAT). Positive IFAT with titers ranging from 1:20 to 1:1280 were observed in 52% of the 118 wild tamarins examined and the parasite was isolated from 38 tamarins. No patent parasitemia was observed among the tamarins from which T. cruzi was isolated. Serum conversion and positive hemoculture was observed for three animals that had yielded negative results some months earlier, which indicates that T. cruzi is actively transmitted among tamarins. In contrast to observations with other sylvatic isolates, those from the tamarins were significantly more virulent and most of them produced mortality in experimentally infected Swiss mice. Some variation in the kDNA restriction profiles among the isolates was observed. Electrophoresis with GPI, G6PDH, IDH, MDH and ME enzymes showed a Z2 profile.

Clinical, biochemical, and electrocardiographic aspects of Trypanosoma cruzi infection in free-ranging golden lion tamarins (Leontopithecus rosalia).

Background  Wild golden lion tamarins from the Biological Reserve of Poço das Antas, Rio de Janeiro, Brazil, have high prevalence of Trypanosoma cruzi infection leading us to clinically assess the disease in this endangered species.

Locomotion of Golden Lion Tamarins (Leontopithecus rosalia)

Our study of the locomotor behavior of golden lion tamarins (Leontopithecus rosalia) was initiated because these unique, highly endangered primates, were perceived to possess locomotor deficiencies upon reintroduction to the wild. The critical status of the wild population (Coimbra-Filho and Mittermeier, 1978, Kleiman et al 1986) led to the establishment of the Pogo das Antas Biological Reserve 70 km outside of Rio de Janiero in 1974. The reserve consists of approximately 5000 ha of disturbed lowland rainforest (Kleiman et al 1986, 1991; and Rylands, 1993 for details on reserve condition and environment). A program of reintroductions designed to resupply the declining wild population (Beck et al, 1991; Kleiman, 1989; Kleiman et al, 1986, 1991) by culling social groups from the world’s captive stock was initiated in 1984. The first reintroductions, although successful, raised concerns that captive animals released into the forest may exhibit locomotor, and other behavioral deficiencies resulting from their lack of experience in such a complex environment (Kleiman et al, 1986). Thus, a program of prerelease and postrelease training was designed to aid in the transition of captive-born animals into the wild. The research program reported in this paper was conceived to describe and quantify locomotion in L. rosalia with these issues in mind.

Translations of Chapter Summaries

Analise cladistica das sequencias dos genes Epsilon-globin a e IRBP fornece informacāe complementar importante para urn esboco das principais linhas da filogenia dos macacos do Novo Mundo. As abordagens morfologicas e de genetica molecular sao razoavelmente consistentes com as evidencias disponiveis atraves do reg istro fossil , significando que as formas modernas fornecem uma boa base para o desenvolvimento de uma classificācao dos platirrineos, e que o entendimento das relacōes entre fosseis podem ser facil itados com a inclusao dos generos viventes nas analises. Os estudos moleculares e morfologicas fortalecem a ideia de tres grandes grupos modernos, possivelmente divergindo num intervalo de tempo relativamente curto . Considerando as discordâncias nos estudos da sistematica de platirrineos nas ultimas decadas - a correta localizacoo filogenetica de Cebus, Saimiri, Aotus e Callicebus - a cornbina#x00E7;oo das evidencias colocam Callicebus definitivamente como parente dos pitecineos. Elas reforcam tambem a ligacoo entre Saimiri e os calitriquineos, o elo entre Cebus e Saimiri, e sua associacoo com calitriquineos como uma linhagem monofiletica do grupo dos «cebideos». Os dados de DNA divergem, porem, com a colocacoo de Aotus como uma linhagem basal desse agrupamento, urn achado inconsistente com as evidencias morfologicas. A analise de DNA tambem aponta a necessidade de uma reconsideracoo da taxonomia do genero Callitrhix, que talvez noo seja monofiletica. Os dados confirmam parcialmente o padroo de ramificacoo do clade dos atelideos, posicionando Alouatta como a linhagem mais velha. Problemas que permanecem dentro dos calitriquineos e atelineos incluem: 1)os afinidades precisas entre os atelineos, Lagothrix, Ateles e Brachyt eles; e 2) a sequencia de ramificacoo dentre os calitriquineos, i.e., Callithrix/Cebuella, Leontopithecus , Saguinus e Callimico.