http://www.nytimes.com/2014/08/28/opinion/the-poisoning-of-africas-vultures.html

NAIROBI, Kenya — IN July of last year, roughly 500 vultures died
after they ate the pesticide-laced carcass of an elephant that had been killed
by poachers in Namibia. It was an example of one poaching technique in Africa
that seems to be on the rise: the poisoning of vultures so that authorities
won’t be alerted to the location of the crime.

The overhead circling of vultures has long been used to locate lost or dead
livestock. In the same way, vultures help law enforcement officers zero in on
poachers.

With their keen eyesight and distinctive vantage point, vultures can locate an
elephant carcass within 30 minutes of the animal’s death. It can take 45 to 70
minutes for the most skilled poachers to hack off two elephant tusks, and when
vultures gather overhead rangers can get that much closer to apprehending the
perpetrators. By poisoning a carcass and killing vultures en masse, poachers are
trying to ensure that next time around there will be fewer of them to contend
with.