Some aspects of the ecology of the Indian Giant Squirrel Ratufa indica (Erxleben, 1777) in the tropical forests of Mudumalai Wildlife Sanctuary, southern India and their conservation implications

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N. Baskaran
S. Venkatesan
J. Mani
S.K. Srivastava
A.A. Desai

Abstract

The Indian Giant Squirrel Ratufa indica, an endemic species to India, is widely distributed from the evergreen to moist and dry deciduous forests of Western and Eastern Ghats and the central Indian hills. We studied its population distribution, activity, feeding, ranging and nesting behaviour across three major habitats in the tropical forests of Mudumalai Wildlife Sanctuary, southern India, during 1998-2000 to manage the species effectively. Extensive survey of the three major habitats—tropical moist, dry deciduous and dry thorn—in the sanctuary shows that its distribution is continuous in moist and dry deciduous forests with good canopy contiguity and patchy along riverine areas in dry thorn and dry deciduous forests with sparse trees and broken canopy. Density estimates using 55 direct sightings from 199 km line transects show a mean of 2.9 (plus or minus 0.313) squirrels/km2. Daylight activity and feeding patterns assessed through 24,098 minutes of focal sampling reveal that animals feed and rest equal amounts of time. The diet constitutes seeds, bark, petioles, leaves and fruits from 25 plants, with Tectona grandis as the principal food source (41%). Its home range size varied from 0.8-1.7 ha with a mean of 1.3ha. Nesting characteristics assessed through 83 nests surveyed along 54km transects showed that the squirrel uses 15 of the 33 tree species found, with higher preference to Schleichera oleosa and Mangifera indica. Nest trees are significantly larger in height, gbh and canopy contiguity than nearest non-nest trees, which are attributed to better protection and escape from predators. Maintenance of diverse natural habitats and reduction in anthropogenic pressure are measures suggested for the conservation of giant squirrel populations in the study area.

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How to Cite
[1]
Baskaran, N., Venkatesan, S., Mani, J., Srivastava, S. and Desai, A. 2011. Some aspects of the ecology of the Indian Giant Squirrel Ratufa indica (Erxleben, 1777) in the tropical forests of Mudumalai Wildlife Sanctuary, southern India and their conservation implications. Journal of Threatened Taxa. 3, 7 (Jul. 2011), 1899–1908. DOI:https://doi.org/10.11609/JoTT.o2593.1899-908.
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Communications
Author Biographies

N. Baskaran

N. Baskaran is presently a senior scientist at the Asian Nature Conservation Foundation, Indian Institute of Science, Bangalore. He has two decades of research experience in studying behavioural ecology of an umbrella species ‘the Asian elephant’ across Eastern, and Western Ghats and Eastern Himalayas. In addition, experienced in assessing biodiversity, habitats and behavioural ecology of mammalian species such as Sloth Bear, Grizzled Giant Squirrel and Four-horned Antelope.

S. Venkatesan

S. Venkatesan is a wildlife biologist, completed his PhD in Marine Biology and continue working on marine organism research and conservation.

J. Mani

J. Mani is a wildlife biologist but has shifted to non-wildlife field since 1999.

S.K. Srivastava

Sanjay K. Srivastava is presently a Cheif Conservator of Forests in Tamil Nadu. He has been specilizing on Geographical Information System and Remote Sensing for the past ten years.

A.A. Desai

Ajay A. Desai is a wildlife biologist specialized on Asian Elephants through studies on behaviour, ecology and conservation over the past three decades. He consults for the conservation projects in Asian Elephant range counties. He is the co-chair of the IUCN SSC Asian Elephant Specialist Group, and Steering Committee Member of Project Elephant Govt. of India.

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