Waxwings and Silky Flycatchers: Bombycillidae

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WAXWINGS AND SILKY FLYCATCHERS: Bombycillidae

CEDAR WAXWING (Bombycilla cedrorum): SPECIES ACCOUNTS
GRAY HYPOCOLIUS (Hypocolius ampelinus): SPECIES ACCOUNTS

PHYSICAL CHARACTERISTICS

Birds of the Bombycillidae family range in size from about 5.9 to 9.4 inches (15 to 24 centimeters) long and can weigh from 1 to 2.1 ounces (30 to 60 grams). They are sleek, elegantly marked songbirds, with short bills, crested heads, and plump bodies. Waxwings generally have buff-gray bodies with black eye and chin masks. Their contrasting wings have white, yellow, or vivid red patches. Except for the Japanese waxwing, their common name refers to the distinctive red appendages on their secondary flight feathers, which look like drops of wax. Biologists do not know if the spots have a purpose, but they are absent in juveniles. The birds' tail bands are usually yellow, but sometimes orange. Waxwings have very high-pitched chatters, whistles, and warbles that many human ears can miss. Silky flycatchers have longer tails, and their crests look more bristly. These birds are generally brown, black, or gray, and some of the four species have yellow or white patches. The gray hypocolius is a gray bird with a black mask and tail band. Ornithologists, scientists who study birds, continue to debate whether the hypocolius makes up a separate family of birds unrelated to the flycatchers and waxwings.

GEOGRAPHIC RANGE

Each of the three groups has a different range. Waxwings are present across temperate regions of North America, Europe, and Asia, while the cedar waxwing winters as far south as Guatemala. Silky flycatchers occupy habitat from the southern United States into Central America, and the gray hypocolius lives in the Middle East and the Indian subcontinent.

HABITAT

Waxwings have become increasingly common in suburban neighborhoods, where they feast on fruits and berry-producing bushes. However, they prefer rows of bushes, shrubs, or trees, and open woodlands. Silky flycatchers and the hypocolius live in dry scrub, characterized by straggly, stunted tree and shrub growth, and desert.

DIET

The staple foods for this family are fruit and berries. Cedar waxwings have a special part of their esophagus in which they store these foods, probably to make the most of the materials they can digest while foraging, searching for food. These birds also eat insects, and will fly after them, pick them off leaves or bark, or dive after them from high perches.

BEHAVIOR AND REPRODUCTION

Birds from the Bombycillidae family are generally outgoing and energetic. Waxwings travel in flocks that can reach into the thousands searching for fruit sources. They are not territorial. Silky flycatchers are more territorial, and nest in casual colonies. Phainopeplas migrate laterally to find wetter habitats after their breeding season ends.

Waxwings are monogamous (muh-NAH-guh-mus), having just one mating partner for the breeding season. The breeding habits of the silky flycatchers and hypocolius are not well known. All of the Bombycillidae species make a small, cup-shaped nest, usually in the strong fork of a tree. Waxwings lay four to six eggs, and silky flycatchers lay two to four. The young birds have no feathers when they hatch, and both parents feed them.

INVASIVE PLANT CHANGING CEDAR WAXWING COLORS

Scientists have noted that waxwing tail bands have been both yellow and orange for the last thirty years. Prior to that time, their tail bands were always yellow. The scientists believe that waxwings have been eating a lot of berries from the introduced (not native) European honeysuckle, which was introduced about then. Scientists think that the birds are being affected by pigments in the orange fruit.

WAXWINGS, SILKY FLYCATCHERS, AND PEOPLE

Because they tend to move suddenly and in large numbers into human areas in search of food, people sometimes view the arrival of these birds as an invasion. Waxwings especially, which tend to fly into windows in suburban areas and to gorge on any berry-producing bushes, are occasionally considered pests.

CONSERVATION STATUS

None of the birds in this family are listed as endangered or threatened. In fact, in North America, populations of cedar waxwings have increased.

CEDAR WAXWING (Bombycilla cedrorum): SPECIES ACCOUNTS

Physical characteristics: Sleek and elegant birds, cedar waxwings have plumage, feathers, with a silky texture. Weighing in at about 1.2 ounces (32 grams), adult waxwings are usually about 6 inches (15 centimeters) long. They are colored in pale shades of gray and brown, with pale yellow on their breast and belly. The inner feathers of its wings, the secondary flight feathers, end in what look like drops of red wax, and a white-edged black mask covers the eye area at a downward angle, giving them a serious appearance. The average life span of the cedar waxwing is one to five years, but occasionally they live up to seven years.

Geographic range: Found only in North America during most times of the year, cedar waxwings breed mainly in Canada and winter in the southern United States and Mexico. They are common in the central and northeastern United States and Pacific Northwest.

Habitat: Cedar waxwings prefer to stay out of forest interiors, but hang around areas on the outskirts to find food and perching sites. They mainly inhabit abandoned fields and open woodland, as well as grasslands, farms, pine tree plantations, orchards, and suburban gardens, especially when these areas are near streams or rivers.

Diet: This species feeds mainly on fleshy fruits while hanging from branches of trees. They particularly favor cedar or juniper berries during the winter, but will also eat insects. During spring, these waxwings seek out the sweet sap of maple trees, hanging from branches to lick up the drops. Biologists have noted that cedar waxwings occasionally become intoxicated by alcohol in overripe fruit, and have observed the birds falling to the ground, flying into windows, or being hit by cars as they sit dazed in the street.

Behavior and reproduction: Cedar waxwings are very social birds and flock together all year. They rarely do anything on the ground, preferring to preen, to smooth and clean their feathers, and look for insects from high, exposed places. Although they are not territorial, parents may show aggressive behavior at their nest, including mouth opening, crest raising, feather ruffling. Their flight pattern consists of short, direct flights from bush to bush using steady wing beats. They have two basic calls: a high-pitched, quickly repeated buzz or trill and a hiss-like whistle.

This species is monogamous within a breeding season, from June through August. They are one of the last bird species in North America to nest because they rely on the ripening of summer fruit as their cue to breed. Males court their mates by performing a hopping dance and delivering an insect or bit of fruit to her. If the female joins the male in the hopping dance, the pair mates for the season and the female begins choosing the nest site.

Female waxwings often have two broods, groups of young birds that hatch together, per season. Females lay a clutch, a group of eggs, of two to six speckled pale blue-gray eggs in a cup-shaped nest woven of grasses and fine twigs. Females incubate, sit on, the eggs for twelve to fifteen days, after which both parents feed and care for the nestlings, young birds unable to leave the nest. The young fledge, grow the feathers needed for flight, after fourteen to seventeen days and usually go off to join another flock. The young will not begin breeding until the following summer. Occasionally, brown cowbirds lay their eggs in the waxwings' nests to trick the waxwings into taking on their parental duties for them.

Cedar waxwings and people: Many people are first acquainted with these beautiful birds after one smashes into their garden-facing windows. Some people consider them pests because of their greedy consumption of berries and fruits. However they are also very helpful in controlling the insect population.

Conservation status: Populations of this species have increased greatly since the pesticide DDT was banned in the 1970s. They are not a threatened species. ∎

GRAY HYPOCOLIUS (Hypocolius ampelinus): SPECIES ACCOUNTS

Physical characteristics: Also known as gray flycatchers, gray hypocoliuses are unique in the family. Adults are generally about 9 inches (23 centimeters) long and weigh about 1.3 to 2 ounces (28 to 55 grams). Gray hypocoliuses are long-tailed birds with a distinctive crest and white markings on their wings. Males are a uniform gray color with a black mask that goes around their heads and a bold black triangular band on their tails. Females are a sandy-brown color with a creamy throat and no mask. Their tail ends are dark. Juveniles are colored like the female.

Geographic range: Gray hypocoliuses are birds of the Middle East and Indian subcontinent, wintering in Saudi Arabia and breeding throughout Iran, Iraq, Turkmenistan, and Pakistan.

Habitat: This species occupies tropical and subtropical areas, especially areas with more dense vegetation and arid, dry, lowlands. They are most often found in river valleys near desert or semidesert, and forage through small tree groupings, irrigated and cultivated areas, palm groves, and broad-leaf scrub.

Diet: Gray hypocoliuses eat mostly fruit, but sometimes insects as well. They rarely go to the ground, instead looking through foliage, leaves, for food. They are known for their careful and deliberate feeding behavior, using their long tails as a lever to balance as they extend their bodies to reach fruit and berries. When eating fruit, the bird chews the pulp and spits out pits, larger seeds, and skin.

Behavior and reproduction: Skittish and shy birds unless accustomed to the presence of humans, gray hypocoliuses are not easy to find and fly immediately to dense vegetation when disturbed. This bird, like its cousins, is outgoing and social, and in winter forms flocks of up to twenty individuals that live in loose colonies. This species has a soft, gentle, cat-like call: "tre-tur-tur" or "whee-oo." Their flight pattern is strong and direct, with quick wing beats and occasional undulating, wave-like, glides.

Gray hypocoliuses breed from May to June, locating the nest within a dense bush or low tree up to 12 feet (4 meters) from the ground. The cup-shaped nest sits atop a base of twigs, and is made of grass and plant down and lined with wool, hair, and more down. The female lays three or four oval-shaped, smooth, glossy eggs that are white to pale gray. Both parents take turns incubating the clutch for fourteen to fifteen days.

Gray hypocoliuses and people: Many devoted birdwatchers wait a lifetime to add a sighting of this bird to their list. Their residence in the politically charged countries of the Middle East makes them particularly difficult to observe.

Conservation status: Gray hypocoliuses are not believed to be threatened, although biologists encounter many political difficulties when attempting to visit the bird's home countries to study it. ∎

FOR MORE INFORMATION

Books:

Baicich, Paul. A Guide to the Nests, Eggs, and Nestlings of North American Birds. Princeton, NJ: Princeton University Press, 1997.

Grimmet, Richard, Carol Inskipp, and Tim Inskipp. Birds of the Indian Subcontinent. London: Christopher Helm Ltd, 1998.

Sibley, C. G., and B. L. Monroe. Distribution and Taxonomy of Birds of the World. New Haven, CT: Yale University Press, 1991.

Zim, Herbert Spencer, Ira Noel Gabrielson, and James Gordon Irving. Birds: A Guide to Familiar Birds of North America. New York: St. Martin's Press, 2001.