[bakul]

I suspect stronger drugs such as codeine etc are used for palliative care of humans in their last stages. Not sure of their effect on vultures. Parsi numbers have never been high and gradually decreasing (now about 70,000 in India), also they mainly live in relatively few places, most in Mumbai and nearby. The vulture population dropped from 40 million to a few hundred so the primary cause must be from their non-human diet.

[boomboomsubban]

I assume NSAID's are still common, though opiates are stronger pain killers, antiinflammatory and fever reducers would still be helpful.

That said, I'm not arguing the official explanation is wrong, just curious if the same thing would happen at the towers.

[dyauspitr]

And by decreasing you mean they are finally being assimilated into the general Indian population.

[bakul]

Low fertility rates (like in most well to do communities), interfaith marriages (if you marry a non-parsi and your kids are not considered parsi), aging population, migration out of India.