Dominance hierarchy and social grooming in female lion- tailed macaques (Macaca silenus) in the Western Ghats, India

This article reports the structure of dominance and its relationship with social grooming in wild lion-tailed macaque females. The strength of dominance hierarchy was 0.79 on a scale of 0 to 1 indicating a moderate linearity in the ranking system. Dominance scores were converted into an ordinal as well as an interval scale. Grooming scores were also converted into interval scales using standard scores. Grooming received and grooming given correlated positively and negatively respectively with dominance ranks indicating that high ranking females received more and gave less grooming. Grooming was also positively related to encounter rates for dyads of females. More grooming among adjacent ranks, and grooming being more reciprocal, occurred only in the case of dominant females. The grooming patterns, therefore, appeared to be more of despotic than egalitarian nature. While ranking macaques into different Grades of social systems ranging from despotic to egalitarian, Thierry (2004) has placed lion-tailed macaques in Grade 3 corresponding to the ‘relaxed’ social system. Our results indicate that the grooming and dominance relationships in this species are more despotic, and hence, the Grade for this species requires to be shifted toward 2 or 1.     

Distribution,population structure,and conservation of lion-tailed macaques (Macaca silenus) in the Anaimalai Hills,Western Ghats,India

The lion-tailed macaque is an endangered species, and hence it is necessary that the remaining populations in the rainforests of the Western Ghats, India, be located and their habitats assessed for effective conservation. The Anaimalai Hills in the state of Tamil Nadu harbor 31 groups of lion-tailed macaques. However, the rainforest in these hills is highly fragmented. Since lion-tailed macaques are typically arboreal, the groups have become isolated. Two large rain-forest complexes in these hills harbor 12 and seven groups, respectively, and the remaining 12 groups inhabit small, isolated forest fragments. Group size ranges from six to 53 individuals, with a mean size of 16.3. In the small forest fragments, the standard deviation (SD) of group size was considerably higher than it was in the larger forest complexes. The disturbed fragments also had a higher variability in group size than the relatively undisturbed habitats. It is believed that fragmentation may impede male migration. We suggest that the fragments be managed in such a way that male migration among groups can be facilitated to overcome the potential effects of isolation.     

Distribution, Habitat Correlates, and Conservation of Loris lydekkerianus in Karnataka, India

We surveyed slender lorises (Loris lydekkerianus) in Karnataka, south India intermittently during November 2001–July 2004 and estimated their relative abundance via direct sightings. Two subspecies, Loris lydekkerianus lydekkerianus and L. l. malabaricus, with different morphological traits, occur in the eastern drier region and the western wet region of the state, respectively. The distribution of Loris lydekkerianus lydekkerianus is patchy in a small region in the southeast, which contradicts earlier reports of its abundance throughout the state. Loris lydekkerianus malabaricus occurs throughout the Western Ghats as a contiguous population. The encounter rates of Loris lydekkerianus lydekkerianus and L. l. malabaricus are 0.41 individuals/km and 0.21 individuals/km, respectively. Whereas several forest tracts in the distributional range of Loris lydekkerianus malabaricus are protected areas, no such area exists in the distributional range of L. l. lydekkerianus. Loris lydekkerianus faces serious challenges of conservation because it largely occurs in commercial plantations, which can be relatively unstable habitats as harvesting can take place at any time.

Somatic embryogenesis in cell suspension culture of carnation (Dianthus caryophyllus L.)

Somatic embryogenesis and plantlet formation were obtained from 60–75 day old cell cultures of carnation. Callus was generated on MS basal medium supplemented with 2,4-dichchlorophenoxy acetic acid (2,4-D). Removal of 2,4-D during subsequent subculturing of cell suspensions resulted in formation of embroids. These somatic embryos originated from single cells and their early development proceeded normally with clearly defined apical and root meristems. Some embryos developed into plants and were acclimatized to ex vitro conditions.Abbreviations BAP 6-benzylaminopurine - Kinetin 6-furfurylamino purine - 2,4-D 2,4-dichlorophenoxy acetic acid - MS Murashige and Skoog     

Extractive foraging and tool-aided behaviors in the wild Nicobar long-tailed macaque (<Emphasis Type="Italic">Macaca fascicularis umbrosus</Emphasis>)

Macaques possess a repertoire of extractive foraging techniques that range from complex manipulation to tool-aided behaviors, to access food items that increase their foraging efficiency substantially. However, the complexity and composition of such techniques vary considerably between species and even between populations. In the present study, we report seven such complex manipulative behaviors that include six extractive foraging behaviors, and teeth flossing, in a population of Nicobar long-tailed macaques. The apparent purpose of these behaviors was an extraction of encased food, processing food, foraging hidden invertebrates, and dental flossing. Among these behaviors, three behaviors viz. wrapping, wiping, and teeth-flossing were tool-aided behaviors, where macaques used both natural and synthetic materials as tools. Occasionally macaques also modified those tools prior to their use. The substrate use patterns of leaf rubbing and teeth flossing were similar to that observed in other macaques. The spontaneous tool modification to perform wrapping was a first time observation. These observations suggest that Nicobar long-tailed macaques have a high level of sensorimotor intelligence which helps to evolve such innovative foraging solutions.     

Inter-population differences in the time budgets of bonnet monkeys (Macaca radiata)

Time budgets for five major activities viz., Passive Sitting, Locomotion, Foraging, Social Behaviour, and Self-directed Behaviours were recorded for bonnet monkeys inhabiting forest, urban, and rural habitats. The time budgets were further classified into those of various age-sex classes. Significant inter-population differences were found in group size, social behaviour, foraging, and locomotion, which are discussed in relation to the habitat features.     

Impact of forest fragment size on between-group encounters in lion-tailed macaques

Between-group encounters are an obvious outcome of intergroup competition. Between-group encounters in primates range from avoidance to fatally aggressive. The prevailing hypotheses explain such encounters as mate defense strategy by males and resource defense strategy by females. However, the rate and nature of between-group encounters may also be influenced by habitat and demographic characteristics. We studied the effect of forest fragment size on group encounters in lion-tailed macaques in the Western Ghats of southern India. The encounter rate decreased as the fragment size increased. Group density and home range overlap correlated positively with the encounter rate. The aggressive encounters were more in the relatively medium-sized fragment where the observed frequency of between-group encounters was higher than the expected frequency than in the small fragment and the large forest complex. Together, these results indicate a complex pattern of effects of fragment size on between-group encounters in primates.