Like all gibbons, the gray gibbon has unusually long arms which are used to move through trees and to forage. This endangered species is being ‘phased out’ at zoos because there are too few in captivity to keep bloodlines vital and the species isn’t showy.
The endangered grey gibbon (Hylobates muelleri muelleri) may not be seen in captivity much longer. There are now too few in captivity to keep their population sustained and too few in the wild to bring more in. With limited space and funding, zoos must make hard choices every year in deciding which species to breed and which to let go, or ‘phase out’.