
The ploughshare tortoise is the world's most endangered tortoise. Experts estimate there are likely fewer than 200 left in the wild.

The golden color and high arch of the shell make the ploughshare a hot commodity on the black market, especially in Asia.

To make the animal less appealing to collectors, conservationists have started defacing the shells of ploughshare tortoises.

Estimates for the number left in the wild vary due to the fact that it's hard to put human tracers on them. Here, scientists from the Turtle Conservancy in Madagascar attach a radio transmitter to an adult ploughshare tortoise in the wild.

The animals, which can sell for up to $50,000 on the black market, are extremely rare. As such, conservation breeding facilities have to take extreme measures to protect those that remain, such as keep them under constant armed guard.

The process of carving into the tortoises' shells is not too invasive, according to conservationists, as the keratin is thick enough to withstand the procedure.

But for young tortoises and hatchlings (the easiest targets for poachers), carving into the shell would be a painful procedure. As a result, conservationists are looking into tattooing these animals instead.