BULBULS: Pycnonotidae

PHYSICAL CHARACTERISTICS

Bulbuls have short, concave (curved in) wings. They have long tails for the size of their bodies. Most of them have tails that are square or rounded. Bulbuls have slender, notched bills. Most bulbuls have stiff bristles near the edges of the beak opening. Their nostrils are either oval or long. Bulbuls' toes and legs are weak and short. Some species are noted for their full and showy crest on their head.

Bulbuls are not noted for their bright colors. The basic colors are dull brown, olive green, and gray, though some of the species do have markings such as yellow underparts, or faces with red, yellow, orange, or white plumage. These brighter colors are only on the throat, undertails, head, or ears. The parts on the upper portions are usually the same color or shades of color. In several species the tail is either rust-red or reddish brown. The size of the various species varies, and a bulbul can range from 3.6 to 11.5 inches (9.3 to 29 centimeters). They can weigh between 0.5 and 2 ounces (14 to 57 grams). The male and female birds vary little in appearance, but the female is usually smaller.

GEOGRAPHIC RANGE

Bulbuls can be found throughout tropical southern Asia in the forest and wooded areas of Africa, particularly in Kenya, and on Madagascar, the Indian Ocean islands, India, Sri Lanka, southern China, the Philippines, Indonesia, and Japan. The common bulbul is one of the most common birds of Africa. An estimated fifty-two species reside in Africa, and China has approximately twenty-seven species.

The red-whiskered bulbul was introduced to Florida in 1960, and by 1973 there were five hundred birds in an increasing population that expanded southward. By the late 1960s, the same species was established in Los Angeles County, California. The red-whiskered bulbul and the red-vented bulbul were both introduced to Oahu, Hawaii, in the late 1960s. The population of both birds is large there.

HABITAT

Bulbuls are arboreal, living in trees. They live in a variety of areas, including forests, open woodlands, and even gardens created by humans. Some African and Indonesian species live in the interior of the forest. Some like open areas just outside the forest, or forest clearings. Species that have adapted to drier habitats can find homes in cultivated areas. Other bulbuls like to live near water and can be found near rivers or forest streams. The African red-eyed bulbul has adapted to a drier climate and can be found in such areas as savanna (grassland with few trees), semiarid scrub, and bushy hillsides. The common bulbul, also referred to as the African bulbul, is spread throughout Africa, making it the most common of the bulbuls on that continent.

DIET

Bulbuls tend to be omnivores, eating both plants and animals. The diet across the various species ranges from fruits and berries to insects and other arthropods (invertebrates, animals without backbones, with jointed bodies), in addition to small vertebrates, animals with a backbone, including frogs, snakes, and lizards. Some bulbuls have very specific diets; the green-tailed bristle-bill eats only insects in a very specific area, which is made up of a narrow horizontal layer of forest vegetation.

BEHAVIOR AND REPRODUCTION

Bulbuls that are found in forests tend to be secretive. By contrast, those found in garden settings or parks can be bold and gregarious, social. Bulbuls can be very social and are found in groups with their own species and with other species. The spotted greenbul, for instance, is extremely gregarious and travels in a group with other greenbuls in flocks that might have from five to fifty birds. This group never stays too long in one place, even when food is plentiful. Other species that are social, the striated bulbul and the yellow-streaked bulbul, also live in active flocks. Many bulbuls show aggressive behavior toward members of their own species in addition to those of other species.

Most bulbuls have distinctive singing voices—from chattering to whistles. The chance of hearing a bulbul in a tropical forest is high, and they are usually heard before they are seen. Though few are musical, some bulbuls have beautiful and melodious songs, including the yellow-spotted nicator in West Africa, and the yellow-crowned bulbul, found in Borneo. The greenbul is noted for its constant singing throughout the day, all year long.

Bulbuls as a whole are not migratory, moving to other places seasonally, though some species that are adapted to the cooler climates and temperate zones would be considered partly migratory. The black bulbul, for instance, migrates in flocks of several hundred birds at a time to southern China in the winter months. Brown-eared bulbuls that have been banded and recaptured have been shown to migrate within the Japanese islands. Other bulbuls are sedentary, stay in one place, and might move only a few hundred yards (meters) over a period of several years. Most bulbuls live and travel in pairs, or in family groups, complete with its juvenile members.

Bulbul reproduction can vary. It depends on the climate and region. Breeding can be connected to rainfall, with some species breeding before and after the monsoon, rainy, season. Some species breed year-round, even through the rainy seasons. Most are monogamous (muh-NAH-guh-mus; having only one mating partner) and territorial. Mating rituals vary as well, with some species chasing each other while calling out in a soft tone. In most species, both parents usually work on the nest, though in some species it is only the female. Bulbuls generally have a clutch size (number of eggs in the nest) of two, with three for the yellow-whiskered bulbul and one for the West African nicator. Some of the Asian species can have clutches of four or five. The incubation period, time spent sitting on the nest before hatching, varies for the different species but can last from eleven to fourteen days.

BULBULS AND PEOPLE

People have been listening to the song and chatter of bulbuls for centuries. They are often prized as pet birds due to their singing. Some of these birds have had roles in folk tales where they live. In Ghana, West Africa, for instance, natives refer to the swamp greenbul as the "talky-talky bird." Children will not eat the meat of the bird due to the superstition that they will never stop talking if they do. Due to both abuses and diminishing populations because of capture for the bird market, the government of Thailand has required permits for owning the birds since 1992—owning some of these species is considered a sign of wealth and prestige in Thailand. Some have been used in bird fights. In 2001, five hundred captured bulbuls were found in passage to the south of Thailand.

CONSERVATION STATUS

Two species are considered Endangered, facing a very high risk of extinction, and five have been described as Vulnerable, facing a high risk of extinction. One of these, the streak-breasted bulbul, is native to four different Philippine islands and has lost much of its habitat. Even though it does live in open areas, under some circumstances forests also appear to be necessary for its survival. In addition to protecting habitat, further study of the birds' behavior is necessary so we can fully understand what they need to continue to survive.

COMMON BULBUL (Pycnonotus barbatus): SPECIES ACCOUNTS

Physical characteristics: The common bulbul is normally 3.6 to 4.2 inches (9.1 to 11 centimeters), and can weigh from 0.8 to 2.1 ounces (23 to 60 grams). They tend to be the size of thrushes with a dark crest on the head, dark eye-ring, and a black bill. Upperparts tend to be grayish brown, with a similarly colored breast, a white belly, and a white or yellow undertail. Both sexes are similar in appearance, though the female is slightly smaller. Young birds are duller in color than adults, and have rusty tones.

Geographic range: The common bulbul can be found in Africa south of 20° north latitude, except in the dry southwestern regions of the continent and near the Cape of Good Hope on Africa's southern tip.

Habitat: The common bulbul thrives in wooded or bush areas, especially those near water.

Diet: Common bulbuls are omnivores, eating various wild and cultivated fruits, flowers, termites, and other insects, in addition to small lizards.

Behavior and reproduction: The common bulbul is monogamous and has been observed to mate for life. Birds pair through a preening ceremony and duet singing. Two to five eggs are laid in a shallow, thin, cup-like nest in a bush or shrub, and the bird lays eggs twice in a season. The incubation period is twelve to fourteen days, most often with only the female sitting on the eggs. Young are cared for by both parents.

Common bulbuls and people: The common bulbul has no particular significance to humans.

Conservation status: This species is not threatened and is plentiful over a wide area. The common bulbul is Kenya's most common bird. ∎

LEAF-LOVE (Phyllastrephus scandens): SPECIES ACCOUNTS

Physical characteristics: The leaf-love species of bulbul generally has a gray head, with a dull gray-olive back, and a bright, rusty tail. The feathers of the tail and rump are full, and the nape of the neck and area near the bill has a light cover of black bristles. The belly of the bird is colored yellow with creamy white undertones. Both sexes are similar. The juvenile bird is also olive-gray with a rusty tone, the chin and the underparts are white, and the undertail is a pale rust.

Leaf-love bulbuls are usually about 5.9 inches (15 centimeters) in length, with a weight range of 1.1 to 1.9 ounces (33 to 53 grams).

Geographic range: Leaf-loves are found in east central Africa, as well as Sudan, western Gambia, Senegal, Guinea, Sierra Leone, Liberia, Mali, Ivory Coast, Ghana, Togo, Nigeria, Cameroon, Gabon, southern Congo, Central African Republic, and Democratic Republic of the Congo.

Habitat: Leaf-love bulbuls live in forests and in the brush and shrub undergrowth, and small trees near water.

Diet: The leaf-love bulbuls are omnivores and scout for food in trees, on the ground, and in any vegetation, feeding on insects and their larvae, small snails, seeds, and berries.

Behavior and reproduction: Leaf-loves are territorial in their habits during breeding season. The nest, which appears as almost being too small, is cup-shaped and suspended in twigs by cobwebs. The female incubates the eggs alone.

Leaf-loves and people: Leaf-loves have no special significance to humans.

Conservation status: The leaf-love bulbul is common throughout its native area, and is not threatened even though its distribution is fragmented. ∎

BLACK BULBUL (Hypsipetes madagascariensis): SPECIES ACCOUNTS

Physical characteristics: The black bulbul is approximately 7.8 to 10 inches in length (20 to 25.4 centimeters). The bird can be slate gray to shimmering black in color, with a crest that is less than full, but fluffy, and has a forked tail. The black bulbul has bright red legs and feet. Variations among the species include some black bulbuls that have a white head. The birds that live in the western regions of the distribution have plumage that is grayer. Both sexes are similar. The juvenile bird lacks a crest or has one that is not as defined or pronounced, with a white-colored throat and plumage that is grayish brown.

Geographic range: Black bulbuls are native throughout Madagascar (from which they have received their scientific name, madagascariensis), the islands of the Indian Ocean, and the mountainous areas of Pakistan, India, Bangladesh, Sri Lanka, India, southern China, Taiwan, Hainan, Myanmar, and Indochina.

Habitat: Black bulbuls prefer tall forests with broad-leaf trees as well as the shade trees of plantations, and tend to live in the mountainous regions of tropical south Asia.

Diet: The black bulbuls are omnivores that feed on seeds and insects.

Behavior and reproduction: Black bulbuls are extremely social, often traveling in large, noisy flocks of several hundred; but they are also known to gather in small groups, also noisy and social. They have a variety of screeching noises, are swift in flight, and are one of the few species of bulbuls to migrate.

Black bulbuls breed from March through September, and build their nest high in the trees, and sometimes in the brush. Each clutch has two to four eggs.

Black bulbuls and people: Black bulbuls have no special significance to humans.

Conservation status: The black bulbul shows no signs of extinction and is common in its native areas. ∎

FOR MORE INFORMATION

Books:

Alsop, Fred J. III. Birds of North America. Smithsonian Books. London and New York: Dorling Kindersley Publishing, 2001.

Bennun, Leon, and Peter Njoroge. Important Birds of Kenya. Bedfordshire, U.K.: Royal Society for the Protection of Birds, 1999.

Campbell, Brude, and Elizabeth Lack, eds. A Dictionary of Birds. Vermillion, SD: Buteo Books, 1985.

Lewis, Adrian, and Derek Pomeroy. A Bird Atlas of Kenya. Lisse, Netherlands: Swets and Zeitlinger, 1988.

Simpson, Ken, and Nicolas Day. The Birds of Australia, A Book of Identification. Dover, NH: Tanager Books, 1984.

Williams, John George, and Norman Arlott. The Collins Field Guide to the Birds of East Africa. Brattleboro, VT: Stephen Greene Press, 1992.

Zimmerman, Dale A., Donald A. Turner, and David J. Pearson. Birds of Kenya and Northern Tanzania. Princeton, NJ: Princeton University Press, 1999.

Web sites:

"Black Bulbul." Science Daily. http://www.sciencedaily.com (accessed on May 5, 2004).

"Leaf-love." Science Daily. http://www.sciencedaily.com (accessed on May 5, 2004).

"Pycnonotus barbatus." Kenya Birds. http://www.kenyabirds.org.uk (accessed on May 5, 2004).