Lost and found. Boulenger's tree frog vanished from the eye of science for more than a century until its rediscovery in 1998 during an expedition highlighting the importance of often-overlooked amphibians. This frog is a marvel of efficiency when moving through the trees, having evolved toe pads as well as extra cartilage in its toe. Another useful adaptation is its ability to change color quickly between light green and orangish brown. But it may well be lost again as its habitat falls to agricultural use.