Part of human-wildlife conflict and especially humanencroachment on wildlife reserves is the inevitable killings of local residents.

"Answering nature's call" probably meant they were actually wood cutting or something similar in the Park.

I imagine "rehabilitation" here refers to the lion being kept in captivity from now on. Perhaps it is an old beast or one susceptible to becoming a maneater.

Locals usually "fix" this sort of issue with poisoned animal carcasses. Resulting in the continual destruction of tiger and lion populations in India.