The vultures the scavangers are alarmingly decreasing in Indian subcontinent. They act as a kind of biosterilizers as most of the pathogens including that of Rabies are destroyed inside their acidic stomachs and so they excrete almost pathogen free carrion and thus help in preventing the spread of infections from carcasses.
The below metioned information has been taken from the website mentioned here below.
RABIES & VULTURE DIE-OFF - INDIA
Date: Wed, 5 Feb 2003
From: Pablo Nart <email@example.com>
Source: The Guardian, 4 Feb 2003 [edited]
Vulture deaths bring rise in rabies
The catastrophic decline of the vulture population in India, vital to
cleaning the streets of offal and rubbish, has led to an explosion in the
number of feral dogs and an increasing human death toll from rabies. An
unknown virus has been killing 3 species of the once numerous vultures in
the last 10 years. This has led to a crisis.
Habitually, butchers threw offal outside for the vultures, which
effectively solved the waste problem. The vulture's niche has now been
taken over by feral dogs, the main carriers of rabies. More people now die
of rabies in India than anywhere else.
Zoroastrians have had to abandon their traditional practice of placing
their dead on Towers of Silence for the vultures to eat.
So alarmed has the government become about the diminished vulture
population they have set up a rehabilitation centre to save sick birds and
release them into the wild.
Britain has donated 145 000 GBP [236 311 USD] for a centre near Delhi, and
Elliot Morley, the department of the environment minister for wildlife,
will officially open it on Saturday,7 Feb 2003. Mr Morley said "There has
been a very high mortality, around 97 per cent of vultures have disappeared."
[byline: Paul Brown]
[While it may be true that an increase in rabies incidence is being
observed in India, the statement "more people now die of rabies in India
than anywhere else" was valid before the vulture die-off. The latest
available World Survey of Rabies that includes India (WHO, 1998) stated
that "the highest incidence continued to be observed in Asia with 33 075
reported human deaths due to rabies. Most of them (estimated 30 000)
occurred in India".
Vulture die-off - India, Pakistan, Nepal (04) 20021018.5590
Vulture die-off - India, Pakistan, Nepal (03) 20021015.5557
Vulture die-off - India, Pakistan, Nepal (02) 20021014.5552
Vulture die-off - India, Pakistan, Nepal: RFI 20021010.5514]