These giant tortoises are so iconic that the islands were named after them ("galapago" means "tortoise" in Spanish). They are the largest tortoises in the world and among the longest living vertebrates, with potential lifespans in excess of 170 years.
In the absence of any major predators, adult tortoises evolved a docile demeanor, which unfortunately made them easy to exploit by early human settlers. It has been estimated that a population in excess of 250,000 once existed on the islands as recently as 200 years ago, but there are about 20,000-25,000 alive today.
The good news is that intense conservation efforts have been successful for most of the subspecies, and the islands' tortoise populations are, for the most part, on the rebound.