Browsing by Subject "Alouatta palliata"
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Item Open Access Distribution, ecology, life history, genetic variation, and risk of extinction of nonhuman primates from Costa Rica(Rev Biol Trop, 2004) Zaldivar, ME; Rocha, O; Glander, KE; Aguilar, G; Huertas, AS; Sanchez, R; Wong, GWe examined the association between geographic distribution, ecological traits, life history, genetic diversity, and risk of extinction in nonhuman primate species from Costa Rica. All of the current nonhuman primate species from Costa Rica are included in the study; spider monkeys (Ateles geoffroyi), howling monkeys (Alouatta palliata), capuchins (Cebus capucinus), and squirrel monkeys (Saimiri oerstedii). Geographic distribution was characterized accessing existing databases. Data on ecology and life history traits were obtained through a literature review. Genetic diversity was characterized using isozyme electrophoresis. Risk of extinction was assessed from the literature. We found that species differed in all these traits. Using these data, we conducted a Pearson correlation between risk of extinction and ecological and life history traits, and genetic variation, for widely distributed species. We found a negative association between risk of extinction and population birth and growth rates; indicating that slower reproducing species had a greater risk of extinction. We found a positive association between genetic variation and risk of extinction; i.e., species showing higher genetic variation had a greater risk of extinction. The relevance of these traits for conservation efforts is discussed.Item Open Access Sexual dimorphism and growth in Alouatta palliata based on 20+ years of field data.(American journal of physical anthropology, 2020-05-31) Runestad Connour, Jacqueline; Glander, Kenneth EOBJECTIVES:Alouatta palliata patterns of growth and sexual dimorphism are evaluated using 20 plus years of field data. Comparisons are made to other species of Alouatta and other New World primates. MATERIALS AND METHODS:Records of 92 A. palliata from Guanacaste Province, Costa Rica, were used to generate growth curves for body mass and linear measurements. Timing of growth for the properties was compared, and males and females were contrasted. Slopes and elevations for periods of rapid growth were evaluated. Growth allometry and proportion ratios were also explored. RESULTS:Body mass growth is rapid during the first 2 years. Males and females begin to diverge around a year of age as male growth increases and female growth slows. Adult mass for both is reached about 4 years of age. Linear measurements show rapid growth the first 18 months for both sexes. Differences develop as males continue the same rate of linear growth while female growth slows. Adult size is reached for head and body length around 3 years, and for hind-foot and tail lengths around 2 years. DISCUSSION:A. palliata males grow in mass more rapidly than females, while both grow similarly in linear dimensions, so that dimorphism is more pronounced in mass. This pattern is seen in other dimorphic New World primates. Male A. palliata may grow more rapidly than A. seniculus, reflecting earlier emigration for A. palliata males. Linear dimensions reach adult proportions earlier than body mass. For hind-foot and tail, this is probably an adaptation for gripping.Item Open Access Sexual Selection in Mantled Howling Monkeys (Alouatta palliata), With an Emphasis on the Role of Female Mate Choice(2010) Ford, Randall ThomasDespite early neglect, recent studies of sexual selection have shown a renewed interest in female reproductive strategies. Clearly the traditional portrayal of female animals as passive participants in mating is incorrect, but much is still unknown about female reproductive strategies, including the extent of female mate choice. The primary goal of this dissertation was to explore the role of female mate choice in mantled howling monkeys (Alouatta palliata), a species in which males have previously been assumed to control mating.
From March 2006 through February 2007, I used continuous focal-animal sampling to record the behavior of adult female mantled howlers at Hacienda La Pacifica, Guanacaste, Costa Rica. The focal animals in the study were nine adult females in a social group that has been regularly monitored since 1984. There were also three capture sessions performed by K. Glander to collect blood samples for genetic paternity analysis. A total of 29 individuals in the study group and eight adult males from surrounding groups were captured.
The genetic paternity analyses were largely inconclusive. Of the eight microsatellite markers used previously in this species, only four were polymorphic in this sample. Additionally, nearly half (7 of 16) of the purported mothers were excluded at one locus. Assuming the mother was unknown allowed determination of genetic paternity in only one case. In terms of behavior, females were largely responsible for soliciting copulations, but female mate choice did not appear to be a major factor. Females almost never rejected copulations (3.3% of copulation attempts) and mated with multiple males in 77.8% of female cycles.
The lack of conclusive genetic paternity data leaves open the possibility of post-copulatory female choice. However, explanations exist for the apparent lack of female mate choice in this species. Because males must attain alpha status to remain in a group, differences in inherent quality may be low among group males. The potential for small differences among males in a social group, combined with the fact that females disperse from their natal group, suggests that female mate choice may occur primarily in choosing a group during dispersal.