Under a worst case scenario, scientists calculate that spider tortoises could disappear in a matter of a few decades: less than a single tortoise's lifespan. As a result, in 2008 it was listed as critically endangered on the IUCN's Red List for Threatened Species. Paltry to start, its range - a 555km long, 10km wide sliver of coast in southwest Madagascar - has shrunk by 71% in the last century. Just eight populations remain, with an average density of just over two tortoises per hectare. Read more