Behavioural studies: a necessity for wildlife management

A major concern of behavioural biology has been the study of evolutionary causative processes in animal behaviour, typically focusing on individuals or social groups. Conservation biology, on the other hand, deals with devising tools for the management of wildlife habitats and populations, and typically focuses on ecosystems. We argue that behavioural studies of individual animals in the appropriate social contexts are necessary for, and integral to, the development of effective management plans for any species. We use the results from our studies on lion-tailed macaques from wild habitats in the Western Ghats, and from captive populations in Europe, to demonstrate how information on behaviour and life-history can be incorporated into improved strategies for wildlife management. We explicitly conclude that one of the major goals of wildlife management should be to create conditions that facilitate the expression of the full range of behavioural patterns in the species being managed, so as to increase the likelihood of population stabilization through the optimization of life-history parameters

Infant development in the slender loris (Loris lydekkerianus lydekkerianus)

In this article we present data on infant development in wild slender loris, a nocturnal primate species. The behavioural ecology of the grey slender loris Loris lydekkerianus lydekkerianus, a nocturnal strepsirrhine, was studied for 21 months (October 1997-June 1999) in a scrub jungle in Dindigul, south India. A total of 22,834 scans were collected during 2656 h of observation on identified and unidentified lorises using instantaneous point and ad libitum sampling methods. Developmental schedules were observed for twelve individuals born during the course of the study period. A greater number of twin births were observed than singleton births and more isosexuals than heterosexuals. Infants were parked at the age of 3 weeks and weaned by 5 months of age. Individuals showed significant developmental differences in their activity schedules. Females appeared to reach sexual maturity by 10 months of age. Social interactions with related conspecifics decreased with age and adult slender lorises did not show differences in social time spent with related and non-related conspecifics

Hierarchy, kinship and social interaction among Japanese monkeys (Macaca fuscata)

The study reports the relationship between hierarchy, genetic relatedness and social interaction in captive Japanese macaques. Grooming and proximity were found to be positively related to both dominance rank and degrees of relatedness. Ranks also positively correlated with threats while no relationship was observed between genetic relationships and agonistic interactions. The removal of α-male tightened the male hierarchy while the female hierarchy became relatively loose. Affiliative behaviour became more correlated with ranks than degrees of genetic relatedness. In the absence of α-male, the next dominant male avoided involvement in either agonistic or afliliative interactions with reintroduced animals and group females

Hunting of Indian giant squirrel (Ratufa indica) by the lion-tailed macaque (Macaca silenus) in the Western Ghats, India

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Division of labour: a democratic approach towards understanding manual asymmetries in non-human primates

A consequence of the \u27gold rush\u27-like hunch for human-like handedness in non-human primates has been that researchers have been continually analysing observations at the level of the population, ignoring the analysis at the level of an individual and, consequently, have potentially missed revelations on the forms and functions of manual asymmetries. Recently, consecutive studies on manual asymmetries in bonnet macaques, Macaca radiata revealed both the functional and adaptive significance of manual asymmetries respectively, and pointed towards the division of labour as being the general principle underlying the observed hand-usage patterns. We review the studies on manual asymmetries in capuchin monkeys, Cebus spp. and argue that the observed hand-usage patterns might reflect specialization of the two hands for accomplishing tasks that require different dexterity types (i.e. manoeuvring in three-dimensional space or physical strength). To this end, we do a step-by-step analysis of the various tasks used in the studies on manual asymmetries in capuchin monkeys. We then describe the division of labour as a general principle underlying manual asymmetries in non-human primates and propose experimental designs that would elaborate the forms and functions of manual asymmetries in non-human primates and the associated adaptive value

An endangered species in captivity: husbandry and management of the lion-tailed macaque (Macaca silenus)

The species that are endangered in their wild habitats also need to be maintained as sustainable populations in captivity. The liontailed macaque (Macaca silenus) endemic to the Western ghats of India, is an endangered species. The captive breeding programmes for this species have been taken up in North America, Europe and India. However, the management practices for the captive population need to be standardized. We propose that an assessment of the biological potential of a captive population at any given time can help predict future population dynamics. Since systematic data on the captive populations of the lion-tailed macaque in European institutions are available for the past several decades, we use those data to trace the development of the population in a historical perspective, and then use this perspective to develop a husbandry and population management manual for the liontailed macaque in captivity. We propose husbandry guidelines for individual groups, and also propose that each group should be considered a part of a metapopulation

Infant development and weaning in Macaca silenus in the natural habitats of the Western Ghats, India

This article reports the development of behaviour in 31 lion-tailed macaque infants from birth to the age of 15 months. The study was conducted during January 2002-June 2005. The study animals included a large group of lion-tailed macaques inhabiting a rainforest fragment in the Western Ghats, India. Two critical stages were observed during the development of the infants: one at the age of five and a half months, and another at the age of nine months. When the infants were five and a half months old, there was a sudden increase in the occurrence of nipple contact, a sharp decline in the per cent of infants making nipple contact after this age, a peak in the occurrence of retrieve by the mother, a peak in the occurrence of play by the infant, and a peak in the occurrence of environmental exploration by the infant, and stabilization of exploration after this age. Up to the age of nine months, the occurrence of an infant approaching the mother and mother punishing the infant continued to increase, and these two behaviours abruptly ended at the age of nine months. Mother grooming the infant occurred with a peak at the infant's age of nine months. It appears that in lion-tailed macaques, the mother actively initiated weaning. It began at the infant's age of five and a half months and was completed by the time the infant was nine months old. The mother, however, increased the frequency of grooming the infant, and thus continued to care for the infant in ways that cost her less in terms of parental investment. A longer duration of nipple contact by some male infants, more retrieval and grooming of male infants, and more proximity of male infants to mothers indicated higher maternal parental investment on male infants

Methodological considerations in measurement of dominance in primates

The strength of dominance hierarchy in a group of animals needs to be quantitatively measured since it influences many other aspects of social interactions. This article discusses three attempts made by previous researchers to measure the strength of hierarchy. We propose a method which attempts to rectify the lacunae in the previous attempts. Data are used from a group of Japanese macaques housed in a colony. A method to calculate strength of hierarchy has been illustrated and a procedure has been suggested to normalize the dominance scores in order to place the ranks of individuals on an interval scale

Stand structure of a primate rich rainforest region in the central Western Ghats of Southern India

The Western Ghats of southern India are one of the most important biodiversity regions in the world, not only due to their faunal diversity and abundance but also due to different habitat types, floral diversity and the presence of several endemic plant species. The rainforests in the central Western Ghats are inhabited by several primate species. We investigated the vegetation pattern and tree species occupancy of one of the prime primate habitats in the central Western Ghats. Lion-tailed Macaque (Macaca silenus), Bonnet Macaque (Macaca radiata), Hanuman Langur (Semnopithecus entellus achates) and Malabar Slender Loris (Loris lydekkerianus malabaricus) inhabit the study area. We studied the density, dominance, frequency and Importance Value Index (IVI) of different tree species, using the belt transect method on randomly selected plots covering 4.1ha. We found that all the plant species that emerged to be the most dominant species with high IVI in the forest were also used by the diurnal primates for foraging. Knema attenuata and Syzygium gardneri were found to be the 'keystone' species. Since the forests of the study area do not come under the 'protected area network' for wildlife, the data obtained during this study will be helpful in the forestry management practices with a view for wildlife conservation of the region