POTOOS: NyctibiidaeGRAY POTOO (Nyctibius griseus): SPECIES ACCOUNT
Like other members of the Caprimulgiformes order, the potoo (poe-TOO) has a large head and large eyes that provide the stronger vision needed for birds that are active at night. Caprimulgiformes have large gapes, which is the width of the mouth when open. A large gape allows birds to catch prey, creatures like insects hunted for food. The potoo's gape is as wide as its head.
While most members of the Caprimulgiformes order have whisker-like bristles on their faces, some potoo species lack bristles, or their bristles are not well-developed. The visible portion of all potoos' bills is small. Potoos have long wings and long, pointed tails. They have short legs and strong toes.
From head to tail, potoos measure from 8 to 23 inches (21 to 57 inches). They weigh 1.6 to 22 ounces (46 to 624 grams). The birds' soft feathers are usually gray, yellowish brown, blackish brown, and white. The rufous potoo is a combination of orange and rufous (reddish brown). Wing color is described in the name of the white-winged potoo.
Bands of colors in the potoo family's feathers form patterns so that potoos resemble the trees where they live. Adult males and females have similar plumage (feather) coloring.
During the nineteenth century, birds in the Nyctibiidae family were called "tree nighthawks." They are now known by the name of one of the species. People thought it sounded like birds in the species were saying the word "potoo."
Potoos live in rainforests, where rain throughout the year produces abundant growth. The birds live in coniferous or evergreen forests, where trees don't undergo seasonal change and shed leaves. Potoos also live in trees in grassland areas called savannas, where there are only a few trees.
Potoos eat flying insects like beetles, moths, termites, crickets, grasshoppers, and fireflies. Birds fly after their prey and catch it in the air. However, they sometimes take prey off of a plant or tree.
BEHAVIOR AND REPRODUCTION
Potoos are nocturnal, becoming active at night. They are solitary feeders, traveling alone while they hunt for food.
During the day, potoos perch on a tree branch or trunk. The bird stands very still on a broken branch or one that slopes. In this motionless position, with its tree-like coloration, the potoo looks like a part of the tree and predators can't see the bird.
Predators that hunt and kill potoos for food include hawks, monkeys, and other mammals that can climb trees.
Even when asleep, the potoo is on the alert for predators. The potoo holds its head so that its bill is pointed upward. Its eyes appear shut, but the potoo looks out from partially open eyes. If predators get too close, the potoo flies away. The bird returns to the same perches for weeks or months.
At night, the potoo hunts for food. The bird chases prey, catching food in its mouth. The potoo then returns to its perch and eats.
Members of the potoo family are noisy at night. They sing loudly, and their calls vary by species. Calls are similar to whistles.
Potoos are monogamous (muh-NAH-guh-mus), a male and female pair up for long-term breeding. The birds build a nest in the hollow of a tree, a branch, or in a broken branch. The female lays usually one white egg there. Both parents incubate the egg, keeping it warm until it hatches. Unlike birds that sit when they incubate, potoos stand upright during incubation. The egg hatches in about thirty days, and the bird grows feathers in forty to fifty-five days.
POTOOS AND PEOPLE
People rarely see the well-hidden potoos. In the past, the birds were the subject of legends and superstition. Some people thought it was bad luck to mock a potoo's call. The call of the great potoo was supposed to be a sign of upcoming trouble or a death.
Today, people interested in the environment visit potoo habitats. They try to view and photograph the birds.
BIRDS WITHOUT NESTS
Potoos do not build nests for their young. Instead of gathering twigs or other nesting material, potoos choose an indented area in a tree for the one egg that the female bird lays. Locations include a broken branch, the forked part of a branch, or a tall tree stump.
After the female lays the egg, both parents incubate it. The potoos are motionless during the daytime, a behavior that young potoos quickly learn.
Potoos are not in danger of extinction (dying out), according to guidelines from the World Conservation Union (IUCN). However, the number of birds has dropped as habitat is lost when trees are cut down.
Physical characteristics: The gray potoo's plumage is brown with streaks of other colors that include gray, black, and reddish brown. The bird has black streaks on the crown (top) of the head and the lower part of the body. The potoo's patterned plumage resembles the tree branches where potoos perch, so the birds can roost (rest) during the day without being seen by predators. Male and female potoos have similar coloring.
The most colorful part of the gray potoo is the iris when the bird is seen at night. The iris is the round portion of the eye surrounding the pupil. If light is shined on the gray potoo, its irises look yellow or orange.
The head-to-tail length of gray potoos ranges from 13 to 16 inches (33 to 41 centimeters). Gray potoos weigh from 5 to 7 ounces (145 to 202 grams). The gray potoo looks much like the northern potoo. However, their calls are so different that each was placed in a separate species.
The gray potoo's call consists of five notes described by people as sounding mournful, or sad.
The gray potoo is also known as the common potoo, the giant nightjar, and poor-me-one.
Geographic range: Gray potoos live in Mexico and Central and South America. Birds are found in the countries of Costa Rica, Panama, Uruguay, Nicaragua, Colombia, Venezuela, French Guiana, Guyana, Ecuador, Peru, Brazil, Bolivia, Argentina, Tobago, Jamaica, Hispaniola, and Trinidad.
Habitat: Gray potoos live in rainforests, coniferous or evergreen forests, and in grassland where there are few trees. Birds also live on plantations, land where people plant trees.
Diet: Gray potoos eat moths, grasshoppers, beetles, termites, and fireflies.
Behavior and reproduction: Gray potoos are solitary and monogamous birds. The breeding season when birds mate varies by location for this species found throughout much of Latin America. In Tobago, gray potoos mate between March and May. The female potoo lays one egg. Both parents incubate the egg that hatches in thirty to thirty-three days. The chick fledges, grows its flying feathers, in forty to fifty-one days.
Gray potoos and people: In Brazil, people thought the mournful song of the gray potoo was actually the sound of a person who had been unlucky in the love. According to the legend, either the love was unrequited (the other person wasn't interested), or the relationship was ended by death or separation. The potoo's sad call was thought to be the song of the unhappy person who had died and had been brought back to life in another form (reincarnated).
Conservation status: Gray potoos are not at risk of extinction. ∎
FOR MORE INFORMATION
Attenborough, David. The Life of Birds. Princeton, NJ: Princeton University Press, 1998.
Young, Bruce E., and James R. Zook. "Nesting of Four Poorly-Known Bird Species on the Caribbean Slope of Costa Rica." Wilson Bulletin (March 1999): 124.
Tobago Home Folklore and History of Trinidad and Tobago. http://www.tobago.hm/folk/bm001bird-c-l.htm#g (accessed on May 25, 2004).