New site record of Grizzled Giant Squirrel Ratufa macroura from Thiruvannamalai Forest Division, Eastern Ghats, Tamil Nadu, India
S. Babu 1 & A. Kalaimani 2
1 S‡lim Ali Centre for Ornithology and Natural History, Anaikatty, Coimbatore, Tamil Nadu 641108, India
2 No: 466/158/89, Murugan Koil Street, Thenimalai, Thiruvannamalai, Tamil Nadu 606603, India
Grizzled Giant Squirrel Ratufa macroura (also known as Sri Lankan Giant Squirrel) is an endemic giant squirrel distributed in southern India and Sri Lanka, and one amongst the two species of diurnal giant tree squirrels (the other being the Indian Giant Squirrel Ratufa indica) distributed in southern India (Prater 1972). The distribution range in India spans the area between Grizzled Squirrel Wildlife Sanctuary in the south (Joshua & Johnsingh 1994) and Hosur Forest Division in the north (Baskaran et al. 2011) (Image 1). Within this range, the grizzled giant squirrel is confined to low elevation riparian forest and low precipitation zones of the Western and Eastern Ghats. The largest populations in southern India are recorded from Chinnar Wildlife Sanctuary (Ramachandran 1989; Senthilkumar et al. 2007) and Grizzled Squirrel Wildlife Sanctuary (Joshua & Johnsingh 1994; Joshua et al. 2008). Beside these, scattered populations are also found in various forest patches (Theni Forest Division (Babu et al. 2013), Anamalai Tiger Reserve (Kumar et al. 2002), Palni Hills (Davidar 1989)) Sirumalai Hills (Sathasivam et al. 2008), Athur & Dharmapuri (Paulraj 1991; Paulraj & Kasinathan 1993), Cauvery Wildlife Sanctuary (Karthikeyan et al. 1992; Kumara & Singh 2006) and Hosur Forest Division (Baskaran et al. 2011) (Fig. 1).
Due to its restricted distribution, small population size and anthropogenic pressure to its natural habitats, the species is classified under the Near Threatened category of IUCN (Joshua et al. 2008). It is listed in Schedule II (Part II) of the Indian Wildlife (Protection) Act (1972). The overall population of the species was estimated as >500 mature individuals with the individual populations having declined by 30% in the last three decades (Joshua et al. 2008). Nonetheless, the current distribution limit of the species is not clearly known, and new records have been published over the years, e.g., the recent record for the species from Hosur and Sirumalai forest divisions (Basakaran et al. 2011; Sathasivam et al. 2008).
Here we present a new site and the eastern-most known distribution for the species from Thiruvannamalai Forest Division, Tamil Nadu. On a bird-watching trip to Sathanur Dam on the morning of 07 October 2012, we came across four dreys of giant squirrels on a Syzygium cumini tree near the dam site. Later, on the way to the crocodile farm (located 200m away from the dam site), at around 12:30hr, a single individual of Grizzled Giant Squirrel was seen foraging on fruits of Ficus racemosa (12.1754760N & 78.8398160E). Geographical location of the sighting and dreys were recorded using GPS VistaHcx; the sighting of the species was confirmed by photograph (Image 1). The animal was observed at a height of 10m on a 14m Ficus racemosa tree, situated next to the road adjacent to the riparian forests. Since at the time of sighting the species we did not have permission to get into the forest area, off the public path, we could not count the exact population inside the riparian patch. Interactions with the locals revealed that they have sighted two to three individuals in the forest patch, but that these rarely came out to the pubic paths/roads.
This observation clearly indicates that the distribution of Grizzled Giant Squirrels in southern India has not been adequately explored and further studies are required in potential areas. Two points in terms of conservation can be emphasised from the present observation; (1) the new record from the Thiruvannamalai Forest Division indicates that it would possibly be the eastern most population of Grizzled Giant Squirrels in southern India; (2) there is a pressing need for further exploration of biodiversity of the Eastern Ghats in Tamil Nadu.
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