Fairy bluebirds and leafbirds

(Irenidae)

Class Aves

Order Passeriformes

Suborder Passeri (Oscines)

Family Irenidae

Thumbnail description
Medium-sized, mostly brightly-colored, thrush-shaped birds, with melodious voices

Size
5.4–10 in (13–25 cm); 0.5–2.6 oz (13.5–75 g)

Number of genera, species
3 genera, 14 species

Habitat
Primarily forests, as well as orchards, gardens and mangrove swamps

Conservation status
Vulnerable: 1 species; Near Threatened: 3 species

Distribution
South and Southeast Asia

Evolution and systematics

In familiar classification systems of the 1950s through the 1970s, the Irenidae were the only bird family entirely restricted to tropical Asia. Traditionally, this family has comprised three genera: the ioras (Aegithina), the leafbirds (Chloropsis), and the fairy bluebirds (Irena). As each is markedly distinct from the other, their inclusion in one family has long been questioned. For years, the leafbirds were commonly considered bulbuls (Pycnonotidae). The status of the fairy bluebirds was particularly controversial. At one time, these birds were popularly known as "blue drongos" (Dicruridae). More recently, various ornithologists have reassigned them to the Old World orioles (Oriolidae), based on skeletal studies. They have also been designated the sole genus in the family Irenidae.

However, the extensive DNA hybridization conducted in the 1980s by Sibley, Ahlquist, and Monroe indicates Irena and Chloropsis comprise a natural grouping, as the great systematist Jean Delacour concluded decades before. On the other hand, the same DNA research, published in 1990, suggests Aegithina is not part of this family, but instead forms a sub-family in the great assemblage Sibley, Ahlquist and Monroe classify under the family Corvidae. No fossils can be attributed to the Irenidae, but DNA hybridization suggests the divergence of these birds as distinct lines in the early Oligocene (roughly 30 million years ago), as well as an origin in Australia (where no modern forms have ever occurred).

Physical characteristics

According to the ornithologist Oliver Austin, two features shared by Aegithina, Chloropsis, and Irena are also typical of bulbuls (Pycnonotidae): the upper tail coverts are long and fluffy, and a patch of hair-like veinless feathers is present on the nape. All are excellent vocalists.

Varying in length from 6 to 7 in (13–18 cm) and averaging half an ounce (13 g) in weight, the four iora species are quietly patterned in shades of yellow and dull green, with some black in the males. With the exception of the great iora (Aegithina lafresnayei), the wings are dark, with boldly contrasting white bars, in both males and females. They have pale gray eyes and thin, uncurved black beaks. Breeding males are generally dark and more brightly colored than females. Un-like leafbirds or fairy bluebirds, nonbreeding male ioras have a comparatively dull eclipse plumage.

Brilliant green plumage in both sexes is a striking feature of all leafbirds. Excluding the Philippine leafbird (Chloropsis flavipennis), the species are distinguished by contrasting head patterns, often involving black throats, and bright blue "moustaches" (malar stripes). Most females do not have black throats, but maintain either the "moustaches" or a blue throat. Another distinction of the males of most species are shiny malachite-green "epaulets" at the bend of the wing. The build manages to be at once graceful and compact. Tails are of moderate length. The feet are notably small in comparison to body

size, and the tarsi are short and fairly strong. The beak is slender and slightly down-curved, and the tongue appears to be specialized for nectar feeding. The size range is 7–8 in (17–20 cm), and weights are 1–1.5 oz (25–40 g).

The plumage of the male Irena puella can be described as a meeting of large fields of blue and velvet-black, accented by brilliant red eyes. The female's feathers are largely greenish cobalt, with black primaries and bright blue elongate rump feathers, as well as an equally red eye. Both sexes of I. cyanogaster are patterned in a comparatively indistinct pattern of deep blue and black. The feet of both are remarkably small in proportion to the generally robust, thrush-like body. At roughly 10 in (25 cm), and 2.5 oz (75 g), the fairy bluebirds are by far the largest members of the Irenidae.

Distribution

Irenids occur throughout the Oriental zoogeographical realm. Each of the three genera is represented by at least one species of very wide zoogeographical range, including the Indian subcontinent, southern China, Indochina, the Malay Peninsula, and the Greater Sundas. Each also includes species of far more limited distribution. Examples are Marshall's iora (Aegithina nigrolutea), found only in tropical Pakistan and northwestern India, and the yellow-throated leafbird (Chloropsis palawanensis), confined to the western Philippine island of Palawan, and some of its tiny satellites. The Philippines represent the eastern boundry of all three genera's range, and none occur in the Lesser Sundas.

Habitat

None of these three genera include habitual ground or undergrowth dwellers, though they may bathe in streams, and leafbirds may rarely forage on the ground or in low bushes. All species of Chloropsis and Irena are birds of the forest canopy, though some leafbirds are also regular garden visitors. Ioras have a far broader habitat tolerance, occurring everywhere from beaches and mangrove swamps to secondary forests, and are a common feature of gardens and orchards.

Behavior

When not nesting, ioras and fairy bluebirds roam the forest in flocks, generally in association with other species. Fairy bluebirds are often found in the company of feeding fruit pigeons, hornbills, bulbuls, and others. Ioras are generally associated with species of similar sized insect-eaters. Leafbirds are likewise nomadic outside the breeding season, but are generally in smaller numbers, or pairs, and are noted for frequent aggression towards other birds. All three genera are known for tuneful songs. Leafbirds are excellent natural mimics of other species. All of these birds form pairs that remain monogamous during the breeding season, and then become territorial.

Feeding ecology and diet

Though ioras have been observed to eat some fruit, they are avid arthropod hunters. Salim Ali describes them foraging through trees, hunting "in the foliage in pairs for caterpillars, moths and spiders, hopping from twig to twig and often hanging upside down in other acrobatic postures among the leaves." Studying bird communities of the dipterocarp forests of north-central Myanmar in the 1990s, David King and John Rappole found common ioras (Aegithina tiphia) were regular components in what they designated "woodshrike flocks," otherwise typically consisting of wood-shrikes, fantails, tits, minivets, nuthatches, and woodpeckers. With the wood-shrikes and minivets, ioras are species that most often initiate a relocation of a flock.

The members of the genus Chloropsis are well-known nectar-feeders. Leafbirds are highly effective pollinators. Groves of appropriate trees around villages have proved very attractive to leafbirds, making them familiar to people. They also hunt insects and spiders and eat small fruits, especially those of the oriental mistletoes (Loranthus sp.).

The abundance of wild fig species that are so important a feature of the southeast Asian forest ecology, are a major component of the diet of fairy bluebirds, flocks of which join the great assemblages of hornbills, fruit pigeons, orangutans, and other animals feasting on one tree after another. Fairy bluebirds will also eat berries from fairly low bushes. They also consume nectar and insects.

Reproductive biology

In India, the common iora may nest from May to September varying slightly with locale, while Marshall's iora, with its dryer range in Pakistan and northwest India, only breeds from June to August. Ioras have a well-known courtship display, which makes a vibrant spectacle of the normally inconspicuous male. During the display the male begins by chasing the female. Then it perches, wings lowered, and fluffs up its lower back feathers, lifts its tail and issues its call, long-drawn hissing phrases. Periodically it jumps up above its perch with its white back feathers fluffed and glides slowly back to its perch in a spiral while calling, sounding like a cricket or tree frog. Iora nests are deep, well constructed cups covered on the outside with spider webs, situated three or four meters up in a tree fork. The clutch is usually two to four gray, brown, or purplish streaked pinkish white eggs.

In India, the blue-winged leafbird (Chloropsis cochinchinensis) nests chiefly from April to August, while the golden-fronted leafbird (C. aurifrons) commences a month later, but also breeds until August. The courtship of the latter appears confrontational, with the male and female chasing and screeching at each other. The nest is a loosely formed cup composed of runners, moss, and rootlets weakly held together with spider webs. Chloropsis eggs are typically pale, speckled or flecked with black and various other colors.

Wild fairy bluebirds (Irena puella) have a short breeding period, typically from February to April (captive birds may breed from April through October). The nest is a loose platform of twigs, overlaid by moss, roots, and detritus, hidden in leafy trees at least five meters up. The usual clutch is of two eggs, olive-gray, irregularly splotched with brown.

Conservation status

The green iora (Aegithina viridissima) and the lesser green leafbird (Chloropsis cyanopogon) have nearly identical ranges, in Thailand to the Malay Peninsula, Sumatra, and Borneo. They are listed as Near Threatened, as is the blue-masked leafbird (C. venusta), a Sumatran endemic. The Philippine leafbird (C. flavipennis) is Vulnerable. In addition to being restricted to threatened habitats, it has always been considered uncommon, in contrast to the other three IUCN listed species, which are considered locally common in parts of their range. Forest destruction has certainly caused losses of optimal habitat for a number of species, but as they are widespread, they are not considered globally threatened.

There is also concern about the cage bird trade. Several species of Chloropsis and fairy bluebirds were found to be popular among the markets of Singapore and Hong Kong in the 1990s. As of 2001, none of these species have been listed in any appendix of the Convention on International Trade in Endangered Species (CITES).

Significance to humans

The highly insectivorous ioras are recognized as a form of natural pest control. The value of leafbirds as pollinators of flowering trees can certainly not be overlooked, though this may be balanced against their spreading the seeds of the parasitic oriental mistletoe from one tree to another.

Appreciation for the beauty of members of the genus Chloropsis is centuries old. Leafbirds have appeared in Chinese art as early as the fifteenth century. The London Zoo obtained an orange-bellied leafbird as early as 1879, and by its centennial, in 1927, had exhibited two other species. In the twentieth century, various leafbirds (traditionally called fruit-suckers) arrived in large commercial shipments to Europe and America. Prior to the Second World War, India was the major source, succeeded by Thailand in the 1950s and 1960s, then by Indonesia and the People's Republic of China in the 1990s. China imposed an export ban on cage birds in 2001, making, for the time being, Indonesia the only commercial source. Due to their pugnacious behavior, they had a justified reputation as being unsuited for small mixed aviaries, and were traditionally kept as pets in small cages.

With the increasing role of ecotourism in the international economy, the potential of fairy bluebirds, leafbirds, and ioras to attract visitors to wildlife areas makes them a valuable resource to preservationists.

Species accounts

List of Species

Common iora

Aegithina tiphia

taxonomy

Motacilla tiphia Linnaeus, 1758, Bengal.

other common names

English: Iora, black-winged iora; French: Petit iora; German: Schwarzflügelaegithina; Spanish: Iora Común.

physical characteristics

5.5–6 in (13–17 cm); 0.5 oz (13.5 g). Males have dark green to black upperparts, bright yellow underparts, black wings with white bars, dark tails, and black crowns. Females have olive-green upperparts, duller yellow underparts, foreheads, and eyebrows, and olive-green crowns.

distribution

Almost all of Indian subcontinent, Sri Lanka, southern Yunnan and southwestern Guanxi, all of Myanmar, Indochina and the Malay Peninsula, Sumatra, Java, Borneo, and Palawan.

habitat

Open woodlands, secondary forest, gardens, orchards, mangroves, and beach forests.

behavior

Outside of breeding season, travels in small flocks or pairs, continuously hunting for small arthropods. Contact is maintained through frequent vocalizations. Distinctive melodious songs and whistles.

feeding ecology and diet

Though some fruit is consumed, diet predominantly small arthropods (spiders, moths, caterpillars, etc.) gleaned from leaves.

reproductive biology

Monogamous. Distinctive courtship behavior: Male repeatedly leaps one or two meters above perch, then glides back down

with feathers erected, assuming a spherical appearance. The nest is deep and cup-shaped. Clutch size two to four. Eggs are pinkish white with brownish or purplish blotches.

conservation status

Not threatened. Has likely expanded its range due to creation of orchards and gardens.

significance to humans

Controls caterpillars and other harmful insects in fruit orchards.

Green iora

Aegithina viridissima

taxonomy

Jora viridissima Bonaparte, 1851, Sumatra.

other common names

French: Iora émeraude; German: Smaragdaegithina; Spanish: Iora Verde.

physical characteristics

5.5 in (13 cm). Dark olive-green plumage with black bill, wings, and tail. Yellow eye ring. Wing bars are white in males and yellow in females.

distribution

Malay Peninsula, including southern Thailand, Sumatra, Borneo, and nearby small islands.

habitat

Lowland primary and tall secondary forest.

behavior

Confined to forest canopy, behavior, including vocalizations, otherwise similar to common iora's.

feeding ecology and diet

Similar to that of common iora, but apparently restricted to forest canopy.

reproductive biology

Similar to common iora.

conservation status

Near Threatened, due to drastic continuing reduction of forest habitat throughout range. Occurs in several important national parks.

significance to humans

None traditionally, but a target species for ecotourists.

Philippine leafbird

Chloropsis flavipennis

taxonomy

Phyllornis flavipennis Tweeddale, 1878, Cebu.

other common names

English: Yellow-quilled leafbird; French: Verdin à ailes jaunes; German: Philippinenblattvogel; Spanish: Verdín Amarillento.

physical characteristics

7.5 in (19 cm). Unique among genus in both sexes lacking clearly defined head pattern. Green plumage with lighter, yellowish throat and yellow eye ring.

distribution

Philippine Islands of Mindanao, Cebu, and Leyte. Possibly extinct on Cebu.

habitat

Canopy of forest and forest edge, from sea level to 4,900 ft (1,500 m).

behavior

Unlike some other leafbirds, very inconspicuous. Individuals or pairs, restricted to forest canopies.

feeding ecology and diet

Little recorded, presumed similar to other species of Chloropsis.

reproductive biology

Nest and eggs unrecorded as of 2000. Breeding season appears to be from June through August.

conservation status

Vulnerable, due to extensive habitat loss over limited range. Probably extinct on Cebu. Occurs in some Mindanao parks.

significance to humans

None known.

Lesser green leafbird

Chloropsis cyanopogon

taxonomy

Phyllornis cyanopogon Temminck, 1829, Sumatra.

other common names

French: Verdin barbe-bleue; German: Blaubart-Blattvogel; Spanish: Verdín Chico.

physical characteristics

6.75 in (17cm). Green plumage with lighter underparts. Black bill and throat with small blue cheek patch. Yellowish tinge around face and throat.

distribution

Thailand, Tenasserim (Peninsular Malaysia), the remainder of the Malay Peninsula, Sumatra, Borneo, and nearby small islands.

habitat

Dense canopies of lowland primary and tall secondary forest.

behavior

Forages from one tree to another individually, in pairs, or in flocks with other species.

feeding ecology and diet

Continuously moves from the top of one tree to another, drinking nectar from blossoms and systematically searching branches for arthropods, often as parts of mixed species "hunting parties."

reproductive biology

Monogamous. Nesting behavior presumed similar to that of other leafbirds.

conservation status

Near Threatened, due to dependence on tall trees in increasingly deforested areas, as well as vigorous exploitation for the bird trade.

significance to humans

Most specimens in the international bird trade become individually housed cage birds in Asia, highly regarded for melodious singing.

Blue-winged leafbird

Chloropsis cochinchinensis

taxonomy

Turdus cochinchinensis Gmelin, 1788, Cochinchina (Vietnam).

other common names

English: Jerdon's leafbird, yellow-headed leafbird, gold-mantled chloropsis; French: Verdin à tête jaune; German: Blauflügel-Blattvogel; Spanish: Verdín de Alas Azules.

physical characteristics

6.5–7 in (16–17.5 cm). Most subspecific variation in family: head color varies from green to yellow and primaries may be blue or green. Distinctive blue outer tail and patch on cheek. Black throat patch in males.

distribution

Peninsular India, Sri Lanka, Bangladesh, Assam, southern Yunnan, Myanmar, all of Indochina and the Malay Peninsula, Sumatra, Borneo, Java, and smaller islands.

habitat

Favors groves and trees around villages and fields in India. Indonesian and Malaysian populations occur in woodland, and primary and tall secondary forest, up to 4,900 ft (1500 m).

behavior

Indian specimens are aggressive and territorial. Indonesian varieties are more social among other species, appearing singly or in pairs, sometimes in groups.

feeding ecology and diet

Enthusiastic nectar feeders, especially from red flowers, serving as major pollinators. Also eat insects and small fruits, especially mistletoe.

reproductive biology

Monogamous. Breeding season more or less from April to August. Nest is a loose, shallow cup composed of fine plant material, plaster on the exterior with cobwebs. Two or three pinkish or creamy-white eggs with variously colored specks, blotches and hair-streaks.

conservation status

Not threatened, but some southern subspecies are in areas of intense habitat loss. Species fairly popular in the cage bird trade.

significance to humans

Important pollinator of flowering trees, but may also spread mistletoe. Traditional caged songbird in India and other Asian countries. Significant international trade, especially in Sumatran yellow-headed subspecies.

Golden-fronted leafbird

Chloropsis aurifrons

taxonomy

Phyllornis aurifrons Temminck, 1829, India.

other common names

English: Gold-fronted chloropsis, green bulbul, gold-fronted fruitsucker; French: Verdin à front d'or; German: Goldstirnblattvogel; Spanish: Verdín de Frente Dorado.

physical characteristics

7.5 in (19 cm). Green plumage with golden-orange forehead, black border around blue throat, and bright blue wing patch.

distribution

Himalayan foothills, larges areas of the Indian subcontinent, Sri Lanka, southwest China, Myanmar, and Indochina, with an isolated population in Sumatra.

habitat

Prefers more forested conditions than blue-winged leafbird, but also more likely to be found in middle canopy than other leafbirds.

behavior

Usually in pairs or small parties. A highly accomplished mimic.

feeding ecology and diet

Vigorously hunts insects and spiders, and equally busy nectar feeder. Also eats some fruits.

reproductive biology

Monogamous. Noisy, frantic courtship involving chasing, screeching, and hanging upside down. Nest is loose shallow cup of tendrils, roots, etc, lined with soft plant material, near tip of branch, but concealed by foliage, in tall tree. Two eggs.

conservation status

Not threatened, though heavily exploited for cage bird trade, and subject to habitat loss in many parts of range.

significance to humans

Important pollinator. Traditionally popular cage bird, both for appearance and as songbird and mimic.

Orange-bellied leafbird

Chloropsis hardwickii

taxonomy

Chloropsis hardwickii Jardine & Selby, 1830, Nepal.

other common names

French: Verdin de Hardwick; German: Blaubartblattvogel; Spanish: Verdín de Pico Anaranjado.

physical characteristics

7.5 in (19 cm). Olive-green upperparts with distinctive yellow-orange belly and undertail-coverts. Black bill and throat patch with blue cheek. Bright blue shoulder patch and dark flight feathers.

distribution

Eastern Himalayas, Myanmar, southern China, Hainan Island, Indochina, Malay Peninsula.

habitat

Highland forests, occurs at higher elevations than golden-fronted leafbird.

behavior

Usually in pairs or small groups. Frequently mimics other species.

feeding ecology and diet

Active, acrobatic, arthropod hunter and nectar feeder.

reproductive biology

Monogamous. Nest very similar to gold-fronted leafbird. Two eggs, spotted with various colors, slightly larger than gold-fronted.

conservation status

Not threatened, but experiencing some habitat loss, though less than lowland species.

significance to humans

Avid pollinator, but also spreads mistletoe. Popular cage bird for centuries.

Blue-masked leafbird

Chloropsis venusta

taxonomy

Phyllornis venusta Bonaparte, 1850, Sumatra.

other common names

French: Verdin à front bleu; German: Blaustirn-Blattvogel; Spanish: Verdín Enmascarado.

physical characteristics

5.5 in (14 cm). Green plumage with blue forehead, cheek, and upper throat.

distribution

Sumatra.

habitat

Hill forests.

behavior

Presumed similar to other leafbirds.

feeding ecology and diet

Presumed typical of genus.

reproductive biology

Not known.

conservation status

Near Threatened, due primarily to deforestation. Locally common in some parts of habitat.

significance to humans

Potential "flagship" species to promote ecotourism in Sumatran elevated forest.

Fairy bluebird

Irena puella

taxonomy

Coracias puella Latham, 1790, Travancore.

other common names

English: Blue-mantled fairy bluebird, common fairy bluebird, Asian fairy-blue-bird; French: Irène vierge; German: Elfenblauvogel; Spanish: Ave Flor de Espalda Negra.

physical characteristics

Solidly built. 10 in (25 cm), 2.5 oz (75 g). Males have black underparts, wings, and tail; upperparts and undertail-coverts are a distinctive ultramarine blue. Females are a uniform dark turquoise-blue with black flight feathers. Both sexes have red eyes.

distribution

Coastal southern India, eastern Himalayas, Myanmar, Yunnan, Indochina, Malay Peninsula, Java, Sumatra, Borneo, and western Philippine island of Palawan.

habitat

Primary and tall secondary forests.

behavior

May occur in flocks of up to thirty birds, largely staying in upper canopy, though descending to bath in streams. Loud melodious whistles are typical.

feeding ecology and diet

While known to eat insects and nectar, primarily fruit eaters, specializing in figs.

reproductive biology

Monogamous. Nest is a loose platform of twigs, lined with fine plant materials, in fork of leafy tree. Clutch is two olive-gray, brown splotched eggs.

conservation status

Not threatened, due to enormous range, but many populations are at risk due to forest destruction.

significance to humans

None known.

Philippine fairy bluebird

Irena cyanogaster

taxonomy

Irena cyanogastra Vigors, 1831, Manilla.

other common names

English: Black-mantled fairy bluebird; French: Irène à ventre bleu; German: Kobalt-Irene; Spanish: Ave Azul de Manto Negro.

physical characteristics

9.75 in (24 cm). Black plumage with dark blue belly, tail, and wing edges. Blue from bill to nape; eyes red.

distribution

Most of the major eastern Philippine islands, from Luzon, south to Mindanao.

habitat

Forest canopy.

behavior

Similar to fairy bluebird.

feeding ecology and diet

As in fairy bluebird.

reproductive biology

Not known.

conservation status

Not threatened. Still considered common on all islands as of 2000.

significance to humans

A target species for ecotourists.

Resources

Books

Ali, S. Field Guide to the Birds of the Eastern Himalayas. New York: Oxford University Press, 1977.

Ali, S. The Book of Indian Birds. New York: Oxford University Press, 1996.

Austin, O.L. Birds of the World. New York: Golden Press, 1961.

Collar, N.J., A.V. Andreev, S. Chan, M.J. Crosby, S. Subramanya, and J.A. Tobias. Threatened Birds of Asia. Barcelona and Cambridge: Lynx Edicions and BirdLife International, 2001.

Kennedy, R.S., P.C. Gonzales, E.C. Dickinson, H.C. Miranda, and T.H. Fisher. A Guide to the Birds of the Philippines. New York: Oxford University Press, 2000.

MacKinnon, J., and K. Phillipps. A Field Guide to the Birds of Borneo, Sumatra, Java and Bali. New York: Oxford University Press, 1993.

Sibley, C.G., and J.E. Ahlquist. Phylogeny and Classification of Birds: A Study in Molecular Evolution. New Haven: Yale University Press, 1990.

Organizations

International Species Inventory System. Web site: <http://www.isis.org>

Josef Harold Lindholm, III, BA