For many years it was believed that Sri Lanka had one species of Mouse-deer, which was shared with Southern India. British taxonomist Colin Groves published a paper in June 2005 in The Raffles Bulletin of Zoology that distinguished three species of Mouse-deer from Sri Lanka and India. The Indian Mouse-deer (Moschiola indica) was split as a new species and is now considered endemic to the Eastern Ghats of India. The mouse-deer found in Sri Lanka was split into two new species. The White-spotted Mouse-deer found (Moshiola meeminna) in the dry zone of Sri Lanka and the Yellow-striped Mouse-deer (Moschiola kathygre) found in the wet zone of Sri Lanka. Both species are endemic to Sri Lanka. This raises the number of endemic mammals found in Sri Lanka to eighteen species.
Possible Fourth Species
Colin Groves also stated that ‘a single skull from Sri Lanka’s Hill Zone may prove to represent a fourth species’. The ‘Mountain Mouse-deer’ is evidently a very scarce animal. Many of the field staff of Horton Plains National Park had not seen one although they regularly encounter other nocturnal mammals including leopard.
A Mountain Mouse-deer was seen under quite dramatic circumstances in February 2008 by wildlife photographer and specialist Gehan de Silva Wijeyeratne, and naturalist Nadeera Weerasinghe. While providing a training session on butterflies and dragonflies for the staff of the Horton Plains National Park, an animal came running and jumped into the pond and swam towards them. It was identified as a Mountain Mouse-deer, being pursued by a Brown Mongoose, about a third of its size.
The mouse-deer swam back to the far shore and faced off with the Mongoose. The Mongoose did not enter the water but at times approached within five to six feet of the mouse-deer which responded by flaring its throat and showing the white on its throat.
After fifteen minutes the mongoose seemed to tire of the chase and left. The Mouse-deer left but returned soon with the mongoose in pursuit and once again dived into the pond. Forty five minutes later the duo left and Gehan de Silva Wijeyeratne and Nadeera Weerasinghe informed the park warden. Around 5 pm the mouse-deer was seen again by the park warden and his staff. Later around 6pm it was taken in for safe custody, and offered no resistance. It had a small gash near the ear and was in an exhausted state.
Scientific Analysis
Given the significance of the live specimen, Gehan de Silva Wijeyeratne informed several scientists of the mouse-deer being temporarily held captive. Two scientists took a blood sample for analysis.
Dr Tharaka Prasad the Deputy Director (Veterinary) of the Department of Wildlife Conservation and Dr. Prithiviraj Fernando who has worked on conservation genetics of elephants and other mammals (www.ccrsl.org), examined the mouse-deer, which was released back into the wild later that day.
The mouse-deer was found to be a pregnant female and measured 56 cm in length. This places it at the upper end of all specimens of mouse-deer which have been measured.
New Species?
The newly split wet zone species is bigger than the species in the dry zone. It is too early to establish whether the Mountain Mouse-deer is a separate species or a sub-species of the wet zone Yellow-striped Mouse-deer. It may even transpire that it has no distinct differences from the form found in the wet lowlands. More work may need to be done to resolve the taxonomic questions by examining DNA from other specimens from the wet and dry zones. Ideally more measurements should also be taken in the field through a small mammal trapping survey in the field.
Courtesy of Jetwing Eco Holidays/Gehan de Silva Wijeyeratne.
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