A team of 10 doctors, headed by Dr Jacob Cherian, professor, Mannuthy veterinary college, have so far sterilised seven deer -- three today, four yesterday. Vets from the forest department and Thiruvananthapuram zoo are also here to assist in the operation.

Sterlisation was thought of after much deliberation as besides the maintenance aspect, the problem of habitat destruction was also looming large, sources at the Society for the Preservation of Hill Palace Premises sources told PTI.

Since the animals -- spotted deer and sambars, numbering 98, had been domesticated, they could not be released into the forest directly.

They said further sterilisation would be done only in a phased manner after studying the change in the behavioural pattern of the sterilised deer during post-operativeperiod.

Moreover, the society had to shell out about Rs 25,000 every month for the maintenance of the deer park, which was affecting other developmental works, they said.