Use of an embedded fruit by Nicobar Long-tailed Macaque Macaca fascicularis umbrosus: II. Demographic influences on choices of coconuts Cocos nucifera and pattern of forays to palm plantations

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Sayantan Das
Rebekah C. David
Ashvita Anand
Saurav Harikumar
Rubina Rajan
Mewa Singh


Adaptive pressures of human-induced rapid environmental changes and insular ecological conditions have led to behavioral innovations among behaviorally flexible nonhuman primates.  Documenting long-term responses of threatened populations is vital for our understanding of species and location-specific adaptive capacities under fluctuating equilibrium.  The Nicobar Long-tailed Macaque  Macaca fascicularis umbrosus, an insular sub-species uses coconuts Cocos nucifera, an embedded cultivar as a food resource and is speculated to have enhanced its dependence as a result of anthropogenic and environmental alterations.  We explored demographic patterns of use and abandonment of different phenophases of fresh coconuts.  To study crop foraging strategies, we recorded daily entry and duration of forays into coconut plantations.  We divided age-classes into early juvenile (13–36 months), late juvenile (37–72 months), and adults (>72 months) and classified phenophase of coconuts into six types.  Consistent with the theory of life history strategies, late juveniles were found to use a greater number of coconuts, which was considerably higher in an urban troop but marginally higher in a forest-plantation dwelling group.  Except in late juveniles, males consumed a higher number of coconuts than females in the remaining age-classes.  Owing to developmental constraints, juveniles of both types used higher proportion of immature coconuts though adults showed equitable distribution across phenophases.  Pattern of entries to plantations and duration of forays were uniform through the day in the urban troop but modulatory in the forest-plantation group, perhaps due to frequent and hostile human interferences.  Observations corroborating adaptations to anthropogenic disturbances are described. 

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Author Biographies

Sayantan Das, Biospychology laboratory, Vijnana Bhavan, Institute of Excellence, University of Mysore, Mansagangothri, Mysuru, Karnataka 570006, India. and. Wildlife Information Liaison Development, No. 12, Thiruvannamalai Nagar, Saravanampatti - Kalapatti Road, Saravanampatti, Coimbatore, Tamil Nadu 641035, India.

Sayantan Das manages the Nicobar Project of the Biopsychology laboratory at the University of Mysore.  He is interested in behavior, ecology and environmental conservation.

Rebekah C. David, Centre for Wildlife Studies, 37/5, Yellappa Garden, Yellappa Chetty Layout, Sivanchetti Gardens, Bengaluru, Karnataka 560042, India.

Rebekah Caroline David was a research assistant with the Nicobar Project co-ordinated through the Biopsychology laboratory at the University of Mysore. He interests lie in human-animal interface and in conservation education.

Ashvita Anand, Foundation for Ecological Research, Advocacy and Learning, No. 170/3, Morattandi, Auroville, Tamil Nadu 605501, India. and InSeason Fish, Tarapore Avenue, Harrington Road, Chetpet, Chennai, 600031, Tamil Nadu 600031, India.

Ashvita Anand was a research assistant with the Nicobar Project coordinated by the Biopsychology laboratory at the University of Mysore. Her research interests broadly include animal behavior, human-animal interactions and wildlife conservation

Saurav Harikumar, CR205B Bioscience Building, Biological Sciences, Department of Biological Sciences, Faculty of Science & Engineering, Culloden Road, Macquarie University, Sydney 2109, Australia.

Saurav Harikumar was a research assistant with the Nicobar Project coordinated by the Biospychology laboratory at the University of Mysore. He is primarily interested in animal conservation and conservation communication.

Rubina Rajan, Amity Institute of Forestry and Wildlife, Amity Road, Sector 125, Noida, Uttar Pradesh 201303, India.

Rubina Rajan was a research assistant with the Nicobar Project coordinated by the Biospsychology laboratory at the University of Mysore. She aspires to work on the human-wildlife interface, behavior of animals and ecology in urban regions

Mewa Singh, Biospychology laboratory, Vijnana Bhavan, Institute of Excellence, University of Mysore, Mansagangothri, Mysuru, Karnataka 570006, India. and Zoo Outreach Organization, No. 12, Thiruvannamalai Nagar, Saravanampatti - Kalapatti Road, Saravanampatti, Coimbatore, Tamil Nadu 641035, India.

Dr. Mewa Singh is the principal advisor/supervisor of the Nicobar project. His primary research has focussed on species distribution, population biology, primate behavior and animal conservation.

Funding data


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