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Gleichen, Germany

Kaumanns W.,LTM Research and Conservation | Singh M.,University of Mysore | Singh M.,Jawaharlal Nehru Centre for Advanced Scientific Research | Singh M.,Indian Institute of Science | Schwibbe M.,German Primate Center
Current Science

Rhesus macaques in their natural environments, as well as in the free-ranging colonyat Cayo Santiago, Puerto Rico are highly seasonal breeders. Many ani-mal species lose breeding seasonality when brought under captive conditions. The present study that cov-ers aperiod of 25 years between 1985 and 2010 reports a quick loss of reproductive seasonalityin Group O of rhesus macaques after the group was shifted from Cayo Santiago to German Primate Cen-tre at Gottingen, Germany in 1984, and maintained indoors with controlled temperature and day-length periods for about four years. We divided the study pe-riod of 25 years into five time-periods of five years each for analysis of the data. Over the subsequent years, births started to concentrate within only a few months indicating an increasingtrend towards return of reproductive seasonality. This increase coincided with the increasing number of births in groups with outdoor facilities. Because other factors such as food, water, etc. were similar in indoor and outdoor condi-tions, we infer that the recovery of seasonality in the outdoor groups was due to the variations in tempera-ture and photoperiod. We report here the presence of reproductive seasonality, its disappearance and return in the same colony and its descendents. Source

Kumara H.N.,Salim Ali Center for Ornithology and Natural History | Sasi R.,University of Madras | Suganthasakthivel R.,Kerala Forest Research Institute | Singh M.,University of Mysore | And 5 more authors.
International Journal of Primatology

The status of the endemic and endangered lion-tailed macaque (Macaca silenus) has not been properly assessed in several regions of the Western Ghats of southern India. We conducted a study in Parambikulam Forest Reserve in the state of Kerala to determine the distribution, demography, and status of lion-tailed macaques. We laid 5km2 grid cells on the map of the study area (644km2) and made four replicated walks in each grid cell using GPS. We gathered data on lion-tailed macaque group locations, demography, and site covariates including trail length, duration of walk, proportion of evergreen forest, height of tallest trees, and human disturbance index. We also performed occupancy modeling using PRESENCE ver. 3.0. We estimated a minimum of 17 groups of macaques in these hills. Low detection and occupancy probabilities indicated a low density of lion-tailed macaques in the study area. Height of the tallest trees correlated positively whereas human disturbance and proportion of evergreen forest correlated negatively with occupancy in grid cells. We also used data from earlier studies carried out in the surrounding Anamalai Tiger Reserve and Nelliyampathy Hills to discuss the conservation status in the large Anamalai Hills Landscape. This landscape harbors an estimated population of 1108 individuals of lion-tailed macaques, which is about one third of the entire estimated wild population of this species. A conservation plan for this landscape could be used as a model for conservation in other regions of the Western Ghats. © 2014, Springer Science+Business Media New York. Source

Sfar N.,University of Cologne | Mangalam M.,University of Mysore | Kaumanns W.,LTM Research and Conservation | Singh M.,University of Mysore | Singh M.,Jawaharlal Nehru Centre for Advanced Scientific Research

There are two major theories that attempt to explain hand preference in non-human primates-the 'task complexity' theory and the 'postural origins' theory. In the present study, we proposed a third hypothesis to explain the evolutionary origin of hand preference in non-human primates, stating that it could have evolved owing to structural and functional adaptations to feeding, which we refer to as the 'niche structure' hypothesis. We attempted to explore this hypothesis by comparing hand preference across species that differ in the feeding ecology and niche structure: red howler monkeys, Alouatta seniculus and yellow-breasted capuchin monkeys, Sapajus xanthosternos. The red howler monkeys used the mouth to obtain food more frequently than the yellow-breasted capuchin monkeys. The red howler monkeys almost never reached for food presented on the opposite side of a wire mesh or inside a portable container, whereas the yellow-breasted capuchin monkeys reached for food presented in all four spatial arrangements (scattered, on the opposite side of a wire mesh, inside a suspended container, and inside a portable container). In contrast to the red howler monkeys that almost never acquired bipedal and clinging posture, the yellow-breasted capuchin monkeys acquired all five body postures (sitting, bipedal, tripedal, clinging, and hanging). Although there was no difference between the proportion of the red howler monkeys and the yellow-breasted capuchin monkeys that preferentially used one hand, the yellow-breasted capuchin monkeys exhibited an overall weaker hand preference than the red howler monkeys. Differences in hand preference diminished with the increasing complexity of the reaching-for-food tasks, i.e., the relatively more complex tasks were perceived as equally complex by both the red howler monkeys and the yellow-breasted capuchin monkeys. These findings suggest that species-specific differences in feeding ecology and niche structure can influence the perception of the complexity of the task and, consequently, hand preference. © 2014 Sfar et al. Source

Singh M.,University of Mysore | Jeyaraj T.,University of Georgia | Prashanth U.,University of Mysore | Kaumanns W.,LTM Research and Conservation
International Journal of Primatology

Socioecology suggests that female distribution in space is determined by the distribution of food resources and the male distribution is influenced by female distribution. Though studies have traditionally focused on females, males have received increasing attention in recent years. We compared male-male relationships in lion-tailed macaques and bonnet macaques. Because bonnet macaques have a high adult male:female sex ratio and are seasonal breeders whereas lion-tailed macaques have a low adult male:female sex ratio and are largely aseasonal breeders, we predicted that bonnet macaque males would be spatially and socially more tolerant of each other and would have less linear dominance relationships than lion-tailed macaques. We recorded male-male and male-female relationships in 1 group of wild macaques of each species via scan sampling and 1-0 sampling. The results revealed that lion-tailed macaque males largely remained at a distance from each other whereas bonnet macaque males remained in close proximity to one another. Lion-tailed macaque males were more agonistic toward each other whereas bonnet macaque males showed more affiliative interactions. The dominance hierarchy among lion-tailed macaque males was more linear than among bonnet macaque males. Our data support the hypothesis that the study of spatial structuring, temporality of interactions, and linearity of social relationships may contribute to a better understanding of macaque social systems. © 2010 Springer Science+Business Media, LLC. Source

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