 In October 2006 , hatchlings were released into the wild for the first time to boost the species and help bring them back from the brink of extinction . Each released blue iguana wears a string of colored beads through its nuchal crest for visual identification at a distance , backed up by an implanted microchip and a high @-@ resolution photograph of its head scales . ( Head scale patterns are as unique among blue iguanas as fingerprints are among humans . ) 
