Woodswallows: Artamidae

views updated

WOODSWALLOWS: Artamidae

DUSKY WOODSWALLOW (Artamus cyanopterus): SPECIES ACCOUNT

PHYSICAL CHARACTERISTICS

Woodswallows are small, robust, mostly nomadic (wandering) birds. They have a stout body, soft plumage (feathers), brush-tipped tongue, short neck, short legs, weak-grasping feet, short toes, and a short, stumpy tail that is sometimes white-tipped. The bill is blue-gray, long, slightly curved, and sharply pointed with a bluish black tip. Wings are long, strong, and pointed (such that when flying they look like a common starling).

Their generally dullish looking colors consist of mostly grays, with mixtures of white, black, or reddish on the upper parts of the body, and white below, with several species having also russet colors. Woodswallows also have patches of powder down feathers. Unlike other feathers, powder down feathers crumble at the tips into a soft powder that the birds use for grooming. Males and females look alike in appearance. Adults are 4.7 to 7.9 inches (13 to 20 centimeters) long and weigh between 0.5 and 1.6 ounces (13 and 46 grams).


GEOGRAPHIC RANGE

Woodswallows are found in Australia and Tasmania, throughout the islands of the South Pacific region, Southeast Asia, and across south China to India and Sri Lanka.


HABITAT

This family lives in a wide variety of habitats including open forests, woodlands, scrublands, mangroves (groups of tropical evergreen trees located near tidal coasts), edges of forests, orchards, urban areas, and clearings. In fact, they prefer any habitat that contains plenty of insects.


DIET

Woodswallows eat flying insects, caterpillars, grasshoppers, nectar (sweet liquid that flowering plants produce), and pollen (powdery substance produced by flowering plants that contains reproductive cells). The birds fly to areas that have plentiful insects to eat. They forage primarily by flying high and sweeping up flying insects but, also at times, by dropping from tree limbs to capture prey on the ground. Their brush-like tongue enables them to lap up nectar and pollen when it is available within its environment (in a style similar to honeyeaters).


BEHAVIOR AND REPRODUCTION

Woodswallows are highly social and swiftly flying birds. When not foraging, they often are seen preening (grooming feathers with bill) each other and perching together, clustered together in large numbers on visible tree branches, wires, utility poles, and other such objects. Although clusters of more than 100 have been recorded, most numbers are in the range of fifteen to twenty. Most species remain in the same area all year-round, but at least three species are widely nomadic; that is, they like to wander in (sometimes) mixed species flocks of 100 or more, often traveling from tropical to temperate (mild) environments at different times of the year. Sometimes, at night, they roost as a community, with dozens of birds huddled together, often on the trunk of a tree or in a hollow. In winter, they often join mixed species flocks in order to forage. They have no true song, but do communicate with a soft twittering call that is sounded almost all of the time while foraging for insects. When predators are nearby, woodswallows often mob about them, frequently attacking them, while making harsh calls in the attempt to drive them away.

Woodswallows are monogamous (muh-NAH-guh-mus; having one mate) birds, becoming less social while in their breeding periods. Their courtship, which is usually begun at the start of rainfall in arid, dry, regions, may involve one bird presenting the other one with a piece of food. Later, one of the pair will start to flutter its partly opened wings and to rotate its spread-out tail. The other partner will respond with similar actions for up to a minute or so. The male will then fly to the female in order to mate. They nest in loose colonies (large groups of birds that live together and are dependent on each other) during the rainy season. Nests are usually clumsily made, shallow, bowl-like structures made of plant fibers such as rootlets, fine twigs, and grasses, lined with thin green plant stems, and placed in trees, shrubs, stumps, fence posts, and rocky crevices (birdwatchers can often see woodswallow eggs through the bottom of the frail nest).

Woodswallows are opportunistic breeders; that is, they take advantage of unpredictable environmental conditions when reproducing. In fact, in arid regions, nests may be built within six days of rainfall and eggs laid within twelve days, which is much shorter in time than the normal nest-building period. Both parents build the nest. Females lay two to four white eggs that are spotted or blotched with a variety of colors, but often reddish. The incubation period (time that it takes to sit on eggs before hatching) is twelve to sixteen days, with both parents helping to incubate (sit on eggs). The fledgling period (time necessary for young bird to grow feathers necessary to fly) is fourteen to twenty days. Both parents, and sometimes one or two helpers, feed and take care of their young, continuing often a month after they can first leave the nest.


WOODSWALLOWS AND PEOPLE

People like to watch the highly visible but soft and modest colorations and daring aerial displays of woodswallows.


CONSERVATION STATUS

Woodswallows are not considered to be threatened. However, species with small habitats are sometimes hurt by adverse changes in their environment and by human development and activities within their habitats.

DUSKY WOODSWALLOW (Artamus cyanopterus): SPECIES ACCOUNT

Physical characteristics: Dusky woodswallows are medium-sized, swallow-like birds that have a smoky blue to smoky brown body; small patch of black in the front of the eyes; dark gray to blackish wings with a white leading edge; dark gray to blackish tail with distinctive white spots at the end; and silvery underwings. The bill is short and pale blue with a black tip. Adults are 6.7 to 7.1 inches (17 to 18 centimeters) long and weigh between 1.1 and 1.6 ounces (31 and 46 grams).


Geographic range: Dusky woodswallows are found in Australia, specifically the eastern and southern portions of the country. They migrate northward for the winter.

Habitat: Dusky woodswallows inhabit open eucalyptus (yoo-kah-LIP-tus) forests (those consisting of tall, aromatic trees) and woodlands, along water courses, and over natural clearings. They especially like rural areas and wet climates.


Diet: Their diet consists of insects, foliage, and nectar. They usually catch flying insects, but will also take prey off the ground.


Behavior and reproduction: Dusky woodswallows are often found in small communal flocks of ten to thirty birds. They are social birds, often roosting in a tight group within a tree hollow or fork. Dusky woodswallows rest during the day, usually perching closely together as a group. They communicate with each other with a chattering call, and will display anxiety when predators or intruders are close by giving out a harsh mobbing call.

Males and females build a small, flimsy, cup-like nest made of plant fibers. The nest, made from August to January, is constructed within a colony of other dusky woodswallows, often within a tree trunk or other similar structure. A small territory surrounding the nest is defended by the mated pair. Parents may use helpers to take care of their young. Females lay three to four blotched white eggs. The incubation period is around sixteen days. The fledgling period is sixteen to twenty days.


Dusky woodswallows and people: There is no known significance between people and dusky woodswallows.


Conservation status: Dusky woodswallows are not considered to be threatened. ∎


FOR MORE INFORMATION

Books:

del Hoyo, Josep, A. Elliott, J. Sargatal, J. Cabot, et al., eds. Handbook of the Birds of the World. Barcelona: Lynx Edicions, 1992.

Dickinson, Edward C., ed. The Howard and Moore Complete Checklist of the Birds of the World, 3rd ed. Princeton, NJ and Oxford, U.K.: Princeton University Press, 2003.

Forshaw, Joseph, ed. Encyclopedia of Birds, 2nd ed. San Diego, CA: Academic Press, 1998.

Harrison, Colin James Oliver. Birds of the World. London and New York: Dorling Kindersley, 1993.

Perrins, Christopher M., and Alex L. A. Middleton, eds. The Encyclopedia of Birds. New York: Facts on File, 1985.

About this article

Woodswallows: Artamidae

Updated About encyclopedia.com content Print Article