Results 111 to 120 of about 383 (150)
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Population Size and Characteristics of Alouatta pigra Before and After a Major Hurricane
International Journal of Primatology, 2007Although some environmental risks and resources are known to affect the evolution of primate social groups, we know little about the effect of major natural disturbances on primate populations. Hurricane Iris hit the Monkey River watershed in southern Belize in October 2001, presenting a unique opportunity to document the effects of a natural disaster ...
Travis Steffens +2 more
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Determination of Fecal Glucocorticoid Metabolites to Evaluate Stress Response in Alouatta pigra
International Journal of Primatology, 2008Measuring fecal glucocorticoid metabolites is now a common practice to assess the stress response in primates. Nevertheless, it is important to validate the utilized immunoassay for each primate species before the technique is applied to populations in the wild.
Rodolfo Martínez-Mota +2 more
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Effects of Ecology on the Gastrointestinal Parasites of Alouatta pigra
International Journal of Primatology, 2007We examined the effects of demographic and ecological variables on the prevalence of intestinal parasites in free-ranging black howlers, Alouatta pigra, from Belize and Mexico. We collected 253 fecal samples from 50 individually identified monkeys during 2003.
Sylvia K. Vitazkova, Susan E. Wade
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Social Relationships Among Male Alouatta pigra
International Journal of Primatology, 2008We investigated male social relationships in 2 groups of black howlers (Alouatta pigra) in Palenque National Park, Mexico, over a 14-mo study characterized by frequent changes in male group membership. Both single males and pairs of males entered our focal groups.
Sarie Van Belle +2 more
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Feeding Competition and Group Size in Alouatta pigra
International Journal of Primatology, 2006Researchers consider group size in primates to be determined by complex relationships among numerous ecological forces. Antipredator benefits and better resource defense are the primary pressures for large groups. Conversely, intragroup limited food availability, can result in greater intragroup feeding competition and individual energy expenditure in ...
Kyle H. Knopff, Mary S. M. Pavelka
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Vigilance and aggregation in black howler monkeys ( Alouatta pigra )
Behavioral Ecology and Sociobiology, 2001Animals are expected to reduce per capita vigilance with increasing group size. Widespread support for this expectation has been found in studies of birds and ungulates. Primate vigilance patterns appear to differ, but studies of primates may have sampled groups with too many members to detect intergroup differences in vigilance. We tested this idea by
Adrian Treves +2 more
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Social modulation of testosterone levels in male black howlers (Alouatta pigra)
Hormones and Behavior, 2011The influence of social factors on the modulation of male testosterone levels has been demonstrated among several vertebrate species. In addition to sexual activity, parental care and reproductive competition affect testosterone secretion. We examined variations in testosterone levels among male black howlers (Alouatta pigra) in various social contexts.
Ariadna, Rangel-Negrín +3 more
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Factors affecting the drinking behavior of black howler monkeys (Alouatta pigra)
Primates, 2013Water is essential for animals, and is particularly critical for thermoregulation. Animals obtain water from three main sources, free water, water contained in food, and water produced in the body during metabolism. Howler monkeys (Alouatta spp.) spend a small proportion of their time drinking water and some populations have not been observed drinking,
Pedro Américo D, Dias +3 more
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Genetic diversity in black howler monkeys (Alouatta pigra) from Belize
American Journal of Physical Anthropology, 1997To assess the level of genetic variation in a threatened black howler monkey (Alouatta pigra) population, we examined 36 allozyme loci and restriction fragment profiles of mitochondrial DNA (mtDNA). Mean heterozygosity at allozyme loci was only 0.021 and 5.6 percent of the loci were polymorphic.
R A, James +3 more
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Population Reduction and Social Disorganization in Alouatta pigra Following a Hurricane
International Journal of Primatology, 2003The opportunity to study the effects of a powerful hurricane on monkey populations, diet, and behavior via pre- and post-hurricane data was presented when hurricane Iris virtually destroyed the forest along Monkey River in southern Belize on October 8, 2001, including a 52-ha area where black howlers have been subjects since 1999. Before the hurricane,
Mary S. M. Pavelka +3 more
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