Poo-oo-oo-oo-oo rings the sorrowful wail through the warm summer night. Everyone told me it was a sloth calling. In the late 1980s a visiting ornithologist enlightened me. “That sorrowful wail comes from the Common Potoo (Nyctibius griseus)” he told me, “one of the best camoflaged birds in the world.” We walked through the night toward the mournful call, and a huge yellow eye reflecting the light from our flashlight appeared. “There’s your sloth”, he laughed pointing to the eye and the dark outline of a hawk-like bird. Three-toed sloths sometimes emit a mournful whistling sound, but no one who’s ever heard it would mistake it for a potoo. Very few had heard of the bird. The common potoo perches on the end of a broken stick and blends in so well that it looks like part of the stick. That’s why so few know of its existence. At Hacienda Barú visitors have, on occasion, observed these birds, zoomed in through a spotting scope, and refused to believe that they are looking at a bird. “I don’t see anything but a broken branch”, they say.
The “nest” consists of a single egg balanced on the stubby end of a branch. The parents take turns incubating it and later feeding the hatchling. The newly hatched chick perches beside the parent, and its white, fluffy plumage against the light brownish background of the adult makes the pair slightly more visible. After about three weeks the parents leave the chick alone on the perch, but return regularly with food. Fledging takes place after another three weeks, and the young bird flies away.
The Common Potoo remains motionless on its perch during the daylight hours, and becomes active once the sun sets. Its prey consists mostly of large insects which it catches by flying out in short sallies.
By Jack Ewing
CONTACT: Jack Ewing – Hacienda Barú - jack@haciendabaru.com
