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One Adult Male (one + adult_male)
Selected AbstractsDefence of Females by Dominant Males of Artibeus jamaicensis (Chiroptera: Phyllostomidae)ETHOLOGY, Issue 5 2000Jorge Ortega Defence of females by dominant males of the Jamaican fruit-eating bat Artibeus jamaicensis was observed in two natural colonies over 2 yr. A log-linear model was used to evaluate the frequency distribution of visits to harems by sex, season and agonistic interaction of dominant males. Harem group size varied from four to 18 females, with one adult male in the small and medium-sized groups and two males in the large groups (> 14 females). A highly significant interaction was noted between the age and sex of the visitor and the response of the dominant male. Male visitors were attacked more often than female and juvenile visitors. Aggressive defence increased during the reproductive seasons, with dominant males showing more agonistic responses towards male visitors. An increase in the frequency of visits by male visitors was noted in harem groups that ranged in size from four to 12 females, but the frequency of male visits declined in harem groups that contained more than 14 females. [source] Geographic distribution and demography of Pithecia aequatorialis (pitheciidae) in Peruvian AmazoniaAMERICAN JOURNAL OF PRIMATOLOGY, Issue 12 2009Rolando Aquino Abstract To study the geographic distribution and demographic characteristics of Pithecia aequatorialis in Peruvian Amazonia, we undertook surveys and transect census in three river basins (Río Itaya, Río Tigre and Río Curaray) between 2004 and 2008. A total of 123 groups of P. aequatorialis was encountered during 1623,km of transect walks. Group size was uniform among the three areas (3.4,3.6 individuals), but surprisingly, population densities were higher in the area with strong hunting pressure (Río Itaya: 7.8,ind./km2, vs. 5.6 and 5.9,km2 in the Río Tigre and Río Curaray basins, respectively). The most common group composition included an adult pair with one offspring. Groups with more than one adult male and/or female accounted for 35% of sightings. Our observations extend P. aequatorialis range in Peru further south to the area between the Río Tigre and Río Corrientes, but exclude the area to the north between the Río Curaray and Río Napo. These findings are in contrast to previous distribution maps. P. aequatorialis was rarely seen in interspecific association during our censuses. Am. J. Primatol. 71:964,968, 2009. © 2009 Wiley-Liss, Inc. [source] Social behavior in fission,fusion groups of red uakari monkeys (Cacajao calvus ucayalii)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 12 2009Mark Bowler Abstract Primates living in large groups that divide to forage must have social systems compatible with this mode of living. Uakari monkeys (Cacajao spp.) live in large groups and exhibit a form of fission,fusion grouping, but their social organization is poorly understood. We present some of the first data on social behavior for this genus based on a study on Cacajao calvus ucayalii. They traveled in multimale multifemale groups of highly variable sizes, with bachelor units on the periphery. Adult males were affiliative, and adult females associated with more than one adult male. Adult females typically traveled with their dependent offspring and an older juvenile within the group. In parties of two or more males, individuals engaged in previously unreported display behaviors and acted together to aggressively chase other males. Breeding was seasonal, and mating occurred away from other group members. We speculate on the social organization of C. calvus ucayalii, in which dispersal may be bisexual and peripheral males are affiliative with one another. Affiliated males appear to cooperate in fighting and displaying to other males for access to females during the breeding season. Am. J. Primatol. 71:976,987, 2009. © 2009 Wiley-Liss, Inc. [source] Habitat fragmentation and population size of the black and gold howler monkey (Alouatta caraya) in a semideciduous forest in Northern ArgentinaAMERICAN JOURNAL OF PRIMATOLOGY, Issue 9 2007Gabriel E. Zunino Abstract A population of black and gold howler monkeys (Alouatta caraya) living near the southern limit of its distribution in a semideciduous forest located in northern Argentina was studied in 2003 to evaluate the possible effects of habitat fragmentation , owing to logging , on its density and social organization within it. Aerial photographs taken in 1982, 1992, and 2001 were used to compare maps of vegetation. These maps were used to evaluate changes in the area covered by forest fragments. From March to June 2003, 10-day monthly surveys of howlers were made in each fragment. A total of 232 individual howlers were counted, belonging to 34 groups plus a solitary adult female. Groups ranged from 2 to 19 individuals (mean = 6.82, SD = 4.23), and 21% of the groups contained more than one adult male. Adults accounted for 55% of the individuals, immatures for 45%, and infants represented 13% of the total. Data obtained were compared with information available for the same population for 1982 and 1995. Results revealed no significant changes in the area of fragments, the crude and ecological density of howlers, and group composition. Group sizes and group composition of howlers suggest that the population remained stable over the past 22 years. The density, number of groups, and individuals appears not to be affected by fragmentation and logging, but crude density was low compared with other less-disturbed habitats. The status of the population remains uncertain owing to isolation, and because there are no protected areas to ensure its stability for the future. Am. J. Primatol. 69:966,975, 2007. © 2007 Wiley-Liss, Inc. [source] | ||||||||||