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Vocal Communication and Ontogeny of Foraging

Carlos Ruiz-Miranda
Lisa G. Rapaport

This study began in October 1999 and is being funded by a five-year National Institute of Mental Health grant to Lisa Rapaport, through the University of New Mexico Anthropology Department. We are working out a collaborative agreement with Paula Procópio de Oliveira and her translocation team (Kierulff, Procópio de Oliveira, Rapaport & Ruiz-Miranda ) in the Reserva Biológica União. We are interested in the issues of alternative behavioral strategies used by offspring to obtain resources, caregiver-offspring conflict, and the relationship between trial and error versus social learning in regard to food acquisition and preferences.

We have had two primary study groups during the first year of the project (LB and Funil). We plan to collect data on three different groups of tamarins at União in 2001. We have seen exciting confirmation with regard to our conjectures about social foraging strategies as a function of age. Infants do appear to monitor adult foraging activities. As our study subjects entered the second half of their first year, they quickly traveled over ever-greater distances to commandeer food and foraging sites from older group members. We look forward to converting impressions into quantitative analysis as the sample size increases.

The project hired three field assistants (Marcio Moraes, Eraldo dos Santos and Rachel Tabet) and one housekeeper in late 1999. The project financed the reconstruction of one house in União Reserve. The NIMH project will use the house for the duration of the field study (which is planned to be 2-3 years).

We have chosen to conduct our experiments at the Centro de Primatologia do Rio de Janeiro (CPRJ). Within the next month or two, we will begin to augment the daily ration of 4-5 groups of Leontopithecus chrysomelas, and possibly Leontopithecus chrysopygus, at the CPRJ to encourage reproduction. Food transfer experiments, similar to those I conducted for my dissertation, will be performed on these groups to determine how food familiarity interacts with age to influence food consumption and feeding preferences of immature lion tamarins.

Although we are interested in the nutritional content of foods eaten by immature golden lion tamarins, we have not been collecting samples of plant or animal foods. We are working out a collaboration with Paula Procópio de Oliveira to nutritionally analyze plant samples collected at the União Reserve. We are developing criteria to select those foods that regularly appear in the tamarin diet. We plan to determine not only caloric content but also percentages of fat, fiber, protein, calcium and phosphorus. Eleonora D'Avila Erbesdobler, a graduate student of Carlos Ruiz Miranda¹s at UENF, will begin caloric analysis of samples of tamarin plant foods collected in União.

Carlos Ruiz coordinated or adviser the following research:

  • Vocal communication and ontogeny – analyses of vocal repertoire recordings from 1995 to 1997.
  • Ontogeny of play behavior in golden lion tamarin. M.S. Thesis of Claudia R. Oliveira (M.S. USP-Ribeirão Preto) - wild and reintroduced tamarins do not show differences in the patterns of their play behavior suggesting that captivity has little impact on this behavior.
  • Foraging behavior of captive born tamarins and their offspring born in the wild. Guilherme V. Faria (IC-UENF), Tara Stoinski (U. of Georgia), Ben Beck (NZP-SI). There looks like there are significant differences in the success of micro-manipulation foraging (searching for food with their hands) between captivity born animals (NC), first-generation offspring born in the wild (G1), and later generation wild-borns (G2). The G2 animals are successful on average every four events of micro-manipulation, while the NC and G1 need 12 bouts of micro-manipulation to be successful.
  • Studies about chemical analysis of the diet of the tamarins offspring. Eleonora Erbesdobler (UENF, Ph.D. student), Paula Procópio de Oliveira (Associação Mico-Leão-Dourado); Alcides Pissinatti (CPRJ), Lisa Rapaport (UNM).
  • Distribution of T. cruzi in the area of the golden lion tamarin population. Collaboration with Cristiane V. Lisboa (UENF, Doutorado), Dra. Ana Jansen (FIOCRUZ), e James Dietz (University of Maryland).
  • Characterization of parasites in golden lion tamarin and common marmosets. Collaboration with Carlos E. Verona (M.S. UENF), Marcia Chame (FIOCRUZ) e James Dietz (UMCP).
  • Physical condition of females of golden lion tamarins and common marmosets. Carlos E. Verona (M.S. UENF), Alcides Pissinatti (FEEMA/CPRJ), Nadia Almosny (UFF), Mike Power (NZP-SI), Olav Oftedal (NZP-SI), Ben Beck (NZP-SI), and James Dietz (University of Maryland). The results show that milk of both species in the wild are similar, however C. jacchus seems to supply milk rich in protein while GLTs's is richer in sugars.
  • Ecological Interaction between L. rosalia and C. jacchus. Carlos Ruiz-Miranda, A. Affonso (IC-UENF), Ben Beck (NZP-SI). Signs of competition during the winter had been observed when common marmosets tend to associate with the foraging tamarins. However, in some ways they also benefit by this association: tamarins feed on tree gum produced from the holes made for the marmosets. These results suggest that the marmoset is a factor of importance for the conservation of the golden lion tamarin, however, we need to expand this research to determine if marmosets can affect the reestablishment of tamarins in their natural habitat.