OWLET-NIGHTJARS: Aegothelidae

PHYSICAL CHARACTERISTICS

The name "owlet-nightjar" refers to the characteristics that these birds share with owls, members of the Strigiformes order, and with nightjars, other members of the Caprimulgiformes order. Owlet-nightjars and other members of this order have large heads and large eyes that provide strong vision at night.

Owlet-nightjars also look somewhat like small owls. Both owlet-nightjars and owls have long, narrow tails and wings. The eyes of owlet-nightjars and owls face forward like a human's eyes do. The owl's eyes are in a facial disk, an arrangement of facial feathers that focuses sounds to its ears. The round shape of the owl's face is very clear; the facial disk is not as clear on the owlet-nightjar.

Owlet-nightjars have short legs, a characteristic of the Caprimulgiformes order. However, their legs are not as short of those of other bird families in this order. Furthermore, owlet-nightjars have long toes and claws on their feet, which is similar to the owls, who have sharp claws called talons (TAL-unz). Some other families in the Caprimulgiformes order have a toe that is serrated like the teeth of a comb.

Frogmouths have wide, curved bills, and owls have a short, hooked bill. Owlet-nightjars have tiny bills surrounded by whisker-like bristles. Their small bill opens to a gape, width of the open mouth, which is as wide as their head.

All members of the owlet-nightjar family have dark eyes and soft plumage, feathers, in various shades of brown. Other plumage colors include gray, tan, and rufous, a reddish brown color. Feathers are patterned with streaks of color. Owlet-nightjars range from 7 to 12 inches (18 to 30 centimeters) in length. They weigh from 1 to 3.5 ounces (29 to 98 grams).

Little is known about some owlet-nightjar species because the birds are nocturnal and remain hidden during the day. However, researchers have been able to observe the Australian owlet-nightjar. Females are usually rufous and males are gray. Both have paler coloring on their undersides. There are pale black bars on the undersides, and they have two black stripes on their heads. Australian owlet-nightjars are 8.3 to 10 inches long (20 to 23 centimeters) and weigh 1.4 to 2.1 ounces (39 to 60 grams).

GEOGRAPHIC RANGE

Owlet-nightjars live in Australia, Moluccas, New Guinea and nearby islands, Tasmania, and New Caledonia.

HABITAT

Owlet-nightjars live in various types of forests. Species in New Guinea range in rainforests, where rain throughout the year produces abundant growth. Owlet-nightjar species live in mountain forests, and in scrubland where there are fewer trees.

DIET

Owlet-nightjars are insectivores, animals that eat insects. Their diet also includes small invertebrates, spineless creatures like millipedes and spiders. The mountain owlet-nightjar of New Guinea eats insects and earthworms.

The diets of some owlet-nightjar species are not known. The birds remain hidden from people during the day and are not always seen at night when they hunt for food.

Owlet-nightjars usually hunt and catch their prey by flying from their tree perches to the ground. Sometimes the owlet-nightjars chase and catch food while flying. The birds catch prey with their bills and swallow it whole.

BEHAVIOR AND REPRODUCTION

Australian owlet-nightjars hunt for food within a specific territory. Birds usually pair up to forage, look for food, at night. During the day, birds remain hidden in nests.

Owlet-nightjars are hole-nesters, building nests in holes in trees and openings in rocks.

Australian owlet-nightjars breed from July through December. The male and female birds build a nest out of green leaves. They build the nest in openings such as the hollow of a tree or the crevice in a rock. The female lays two to five eggs in the nest. Both parents incubate the eggs, sitting on them to keep them warm. The eggs hatch after about four weeks. Owlet-nightjar chicks stay in the nest for about three to five weeks. These owlet-nightjars have one brood, set of chicks, each year.

Threats to owlet-nightjars include predators like domestic cats that hunt the birds and eat them. In addition, when owlet-nightjars hunt for food, they may be killed by drivers who do not see the birds flying at night.

OWLET-NIGHTJARS AND PEOPLE

Owlet-nightjars have little contact with people.

CONSERVATION STATUS

The New Caledonian owlet-nightjar is Critically Endangered, facing an extremely high risk of extinction in the wild, according to the World Conservation Union (IUCN). The New Caledonian owlet-nightjar population was thought to be extinct.

The New Caledonian owlet-nightjar was identified in 1880 when a specimen, a single bird, was collected. No other birds were seen and the New Caledonian owlet-nightjar was declared extinct. However, the species had not died out. A New Caledonian owlet-nightjar was seen in 1998, and the conservation status was changed.

Australian owlet-nightjars live throughout Australia and New Guinea, are not considered endangered.

Other species hide so well that it is not known whether they are endangered. However, owlet-nightjar populations will be affected if habitat is lost due to deforestation, the removal of trees from forests.

FELINE OWLET-NIGHTJAR (Aegotheles insignis): SPECIES ACCOUNT

Physical characteristics: Feline owlet-nightjars look somewhat like cats. Their faces have a feline shape. Tufts of feathers above the eyes look like cats' ears, and they have whiskery bristles around the bill. Feline owlet-nightjars have long feathers that appear fluffy. Plumage color ranges from rufous to brown. Feather patterns include brown and black vermicular, twisted, lines and white spots on the body. There are two white stripes on the head, and birds have white bars on their tails.

Feline owlet-nightjars are about 12 inches (30 centimeters) long. They weigh from 2.1 to 3.5 ounces (59 to 98 grams).

Geographic range: Feline owlet-nightjars live in New Guinea.

Habitat: Feline owlet-nightjars live in montane, or mountain, rainforests. The trees are evergreen, and do not change with the seasons.

Diet: Feline owlet-nightjars eat beetles and other insects.

Behavior and reproduction: There is no information available regarding feline owlet-nightjars' behavior or breeding and nesting patterns.

Feline owlet-nightjars and people: There is no known relationship between feline owlet-nightjars and people. However, research may change that and provide additional information about feline owlet-nightjars.

Conservation status: Feline owlet-nightjars are not in danger of extinction. ∎

FOR MORE INFORMATION

Periodicals:

Brigham, R. Mark, Gerhard Körtner, Tracy A. Maddocks, and Fritz Geiser. "Seasonal Use of Torpor by Free-Ranging Australian Owlet-Nightjars." Physiological and Biochemical Zoology (September/October 2000): 613–620.

Pratt, Thane K. "Evidence For a Previously Unrecognized Species of Owlet-Nightjar." The Auk (January 2000): 1–11.

Web sites:

"Australian Owlet-Nightjar." Australian Museum Online. http://www.amonline.net.au/factsheets/owlet_nightjar.htm (accessed on June 1, 2004).

"New Caledonian Owlet-Nightjar (Aegotheles savesi)." BirdLife International. http://www.birdlife.org/datazone/search/species_search.html?action=SpcHTMDetails.asp&sid=2328&m=0 (accessed on June 5, 2004).