Sunday, March 30, 2014
Really Weird Animals - Potoo
Potoos are a group of seven species of tree-dwelling birds native to the Neotropics of Central and South America. They are not much to look at and you’ll struggle to see them at all! They are not brightly colored like many tropical birds or fierce like raptors, but they are masters of disguise. Their complex feather patterns of grays, browns, and black resemble tree bark perfectly. They can stand perfectly camouflaged atop a dead tree branch. A potoo will position itself to mimic an extension of the tree branch itself.
A Common Potoo camouflaged on a stump (wikipedia.org)
They are nocturnal and spend the day resting, out in the open on the end of a dead tree limb. They have unusual slits in their eyelids which allow them to sense movement even when their eyes are closed. The instant a potoo detects an intruder it slowly moves its head straight up and freezes. With its beak pointing up to the sky, it stays perfectly still until the threat passes, looking like no more than the end of a broken branch. They can move their heads unperceptively slow in order to watch a predator carefully. They will squint their eyes as to not expose themselves by revealing too much of their bright yellow irises. These birds are so amazing at camouflage that they show complete composure under pressure and only break free from their disguise if a predator is almost upon them.
A Long-tailed Potoo (wikipedia.org)
The Rufous Potoo is the smallest of the seven species and is invisible among dead leaves and trees. To increase their camouflage even further, they may rock back and forth while roosting to even closer resemble a dead leaf that’s waving in the breeze.
Potoos are very selective nesters. They will not build a nest, but will find an upright broken tree branch with just enough depression or crevice for a single egg to rest. Both parents will take turns shielding the egg from predators and bad weather. Potoos feed on flying insects at dusk and at night. They will regurgitate partially digested food to feed the chick. When the chick is too large to hide under its parent’s protection, it will assume the same freeze position resembling a clump of fungus, since it has gray downy feathers.
Potoos have proportionately large heads for their body size and long wings and tails. The large head is dominated by enormous eyes and a massive broad bill, helping them to see prey in little light and to then catch and swallow that prey whole. Beetles and other flying insects are their main source of food. However, one Northern potoo was found with a small bird in its stomach!
Fortunately all seven species of potoos are not on the endangered or threatened species list, but like all tropical wildlife, they are still subject to rapid loss of habitat by deforestation.
Submitted by Sara Oliver, Naturalist