Asian Fairy-bluebird Irena puella Scientific name definitions

This striking blue-and-black bird is a classic forest species of the Asian tropics. It is by far the most widespread representative of the tiny Fairy-bluebird family (Irenidae); found from the Western Ghats of India to Java and Borneo. The other two species in the family are found exclusively in the Philippines. Asian Fairy-bluebird is a species of lush forest, with a diet comprised largely of fruit. It is a common member of mixed-species flocks, and is often detected by its loud whistled and bubbling vocalizations.

Females are predominantly an azure slaty turquoise, while males are glossy ultramarine above with black on the face, wings, tail, and underparts.

The Maroon-breasted Philentoma (Philentoma velata) co-occurs with Asian Fairy-bluebird over the Sundaic part of its range and has similarly conspicuous large red eyes and blue upperparts, but is slightly smaller, the male has a different color pattern, and the species has a more flycatcher-like shape and typical stance, with a thinner, non-arched, straighter bill. The female Maroon-breasted Philentoma (Philentoma velata) can look surprisingly like a female Asian Fairy-bluebird; however, the bill shape can be a good differentiating feature.

With poor field views, Asian Fairy-bluebird could look dark and blackish and be mistaken for various drongos (Dicruridae), or starlings and mynas (Sturnidae).

With clear views, the Asian Fairy-bluebird is similar only to Palawan Fairy-bluebird (Irena tweeddalii) and Philippine Fairy-bluebird (Irena cyanogastra), but these three species are completely allopatric, with Asian occurring throughout tropical Asia except for the Philippine Islands; Palawan Fairy-bluebird occurring on the Philippine islands of Palawan, Calamians, and Balabac; and Philippine occurring in the north, east, and south Philippines but not the west-central islands closest to Palawan. Male Asian Fairy-bluebird differs obviously from both sexes of the nearly monomorphic Philippine Fairy-bluebird in its brilliant blue mantle and almost entirely black wings, the reverse of the situation in Philippine Fairy-bluebird. Female Asian Fairy-bluebird is much drabber than adult Philippine Fairy-bluebird, and lacks brilliant blue and contrasting black areas. Male Asian Fairy-bluebird differs from Palawan Fairy-bluebird by having violet-tinted royal blue versus cold azure to turquoise-blue “blue areas” (crown, mantle, and scapulars to uppertail coverts and undertail coverts). Female Asian Fairy-bluebird is slightly brighter below, has longer upper- and undertail coverts; and a shorter bill.

Asian Fairy-bluebird has 10 primaries (numbered distally, from innermost p1 to outermost p10, the p9 shortened and the p10 reduced in length), 9 secondaries (numbered proximally, from outermost s1 to innermost s9 and including 3 tertials, s7‒s9 in passerines), and 12 rectrices (numbered distally, from innermost r1 to outermost r6 on each side of the tail). Geographic variation in plumages is slight (see Systematics). The following plumage descriptions are based on those of all subspecies, as found in Wells (1 Wells, D. R. (2005). Family Irenidae (Fairy-bluebirds). In Handbook of the Birds of the World, Volume 10, Cuckoo-shrikes to Thrushes (del Hoyo, J., A. Elliott, D. A. Christie, Editors), Lynx Edicions, Barcelona. pp. 268–277. Close , 2 Wells, D. R. (2007). The Birds of the Thai-Malay Peninsula. Volume 2. Passerines. Christopher Helm, London, UK. Close ), along with examination of Macaulay Library images. See Molts for molt and plumage terminology. Definitive appearance appears to be attained following the Second Prebasic Molt (if not later in some males). Sexes appear to be alike in Juvenile Plumage, differ slightly in Formative Plumage, and differ markedly in Definitive Basic Plumage; plumage succession in Asian Fairy-bluebird along with some historical misconceptions are discussed by Wells (1 Wells, D. R. (2005). Family Irenidae (Fairy-bluebirds). In Handbook of the Birds of the World, Volume 10, Cuckoo-shrikes to Thrushes (del Hoyo, J., A. Elliott, D. A. Christie, Editors), Lynx Edicions, Barcelona. pp. 268–277. Close ).

Natal Down

Undescribed in Asian Fairy-bluebird.

Juvenile (First Basic) Plumage

Juvenile is like female, except that body plumage is duskier and the wings and tail are browner. Juvenile flight feathers may also average narrower, and/or with more tapered or pointed tips but these differences appear slight in fairy-bluebirds, at least when feathers are fresh (see Formative Plumage). In addition, iris color is brown in juveniles (see Bare Parts).

Formative Plumage

Formative Plumage is similar to definitive basic female but averages duller, especially in females (see below). Juvenile primaries, primary coverts, secondaries (except perhaps 1-3 tertials in some birds), and rectrices are retained, providing the best means to identify first-year birds. These retained juvenile feathers are relatively worn, browner, narrower, and more tapered or rounded at the tips than basic feathers of older birds. Most upperwing secondary coverts appear to be retained or some inner lesser and median coverts are replaced, the juvenile coverts worn, brown and contrasting with the bluer replaced scapulars or inner coverts. In addition, iris color is brown to reddish brown during the first year while in Formative Plumage (see Bare Parts).

Formative females appear to average duller than formative males, but there may be overlap (see also 1 Wells, D. R. (2005). Family Irenidae (Fairy-bluebirds). In Handbook of the Birds of the World, Volume 10, Cuckoo-shrikes to Thrushes (del Hoyo, J., A. Elliott, D. A. Christie, Editors), Lynx Edicions, Barcelona. pp. 268–277. Close ). Formative males may appear more like definitive basic females whereas formative females show duller blue body feathers and browner flight feathers. Separation of formative males from definitive basic females may best be accomplished by ageing first, by presence or absence of molt limits, condition of flight feathers, and iris color, and then determining sex.

Definitive Basic Plumage

Female

Head, body, upperwing secondary coverts, tertials and central rectrices subdued verditer blue, the feather edging slightly brighter on rump, uppertail coverts, and underparts. Lighting can affect perceived coloration, from deep blue to reflecting greenish blue or aqua. Remaining (outer) rectrices, primary coverts, primaries, and secondaries blackish, the primary coverts, rectrices, and inner secondaries edged blue when fresh. Definitive Basic Plumageis separated form Formative Plumage (especially for males) by having brighter blue body feathering, upperwing coverts and scapulars, uniform in wear and coloration, and flight feathers blacker, glossier, and with blue edging when fresh, the outer primaries and rectrices broader, relatively fresher, and more truncate at the tips. In addition, iris color is brighter orange-red than in Formative Plumage; as in males (see below) females in Second Basic Plumage may average duller plumage and iris color than older birds (see image under Bare Parts).

Male

Definitive basic male is strikingly patterned, differing markedly from other plumages. Frontal band over bill base, conjoined lores and sides of head to well above eye, side of neck, and entire underparts (except undertail coverts glossy jet black, contrasting with center of crown, nape, back, and uppertail coverts brilliant, “enamel-glossed” blue, the this coloration enhanced by modified outer feather barbs (uppertail coverts can be elongated to tail tip on the Indonesian subspecies; see 1 Wells, D. R. (2005). Family Irenidae (Fairy-bluebirds). In Handbook of the Birds of the World, Volume 10, Cuckoo-shrikes to Thrushes (del Hoyo, J., A. Elliott, D. A. Christie, Editors), Lynx Edicions, Barcelona. pp. 268–277. Close and Systematics). Some individuals have black or gray shaft streaks on body and/or upperwing coverts, resulting in slightly streaked appearance that may have been considered juvenile by some accounts (e.g. 3 Baker, E. C. S. (1922-1935). The Fauna of British India, Including Ceylon and Burma. Birds. 2nd edition. 8 Vols. Taylor & Francis, London, UK. Close , but see 1 Wells, D. R. (2005). Family Irenidae (Fairy-bluebirds). In Handbook of the Birds of the World, Volume 10, Cuckoo-shrikes to Thrushes (del Hoyo, J., A. Elliott, D. A. Christie, Editors), Lynx Edicions, Barcelona. pp. 268–277. Close ). Upperwing lesser and median coverts blue as in back; greater coverts, remiges, and rectrices black except inner 4-5 greater coverts usually tipped blue. Basic primaries and rectrices are broad and truncated at the tips, as in definitive basic females.

It may be possible that Second Basic males average duller and less glossy plumage coloration than older males (see 1 Wells, D. R. (2005). Family Irenidae (Fairy-bluebirds). In Handbook of the Birds of the World, Volume 10, Cuckoo-shrikes to Thrushes (del Hoyo, J., A. Elliott, D. A. Christie, Editors), Lynx Edicions, Barcelona. pp. 268–277. Close ), and the age some birds in Second Basic Plumage may also be inferred by having duller brownish-red to red iris color; beware, however, that iris color may become duller during periods surrounding prebasic molts. Further study is required.

Molt and plumage terminology follows Humphrey and Parkes (4 Humphrey, P. S., and K. C. Parkes (1959). An approach to the study of molts and plumages. Auk 76(1):1–31. Close ) as modified by Howell et al. (5 Howell, S. N. G., C. Corben, P. Pyle, and D. I. Rogers (2003). The first basic problem: a review of molt and plumage homologies. Condor 105:635–653. Close ). Under this nomenclature, terminology is based on evolution of molts along ancestral lineages of birds from ecdysis (molts) of reptiles, rather than on molts relative to breeding season, location, or time of the year (see 6 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close , 7 Pyle, P. (2022). Defining moults in migratory birds: a sequence-based approach. Journal of Avian Biology 2022(5):e02958. Close for more information). There is little or no published information on the molts of Asian Fairy-bluebird but based on examination of Macaulay Library images it appears to show a Complex Basic Molt Strategy with a partial preformative molt and complete prebasic molts but no prealternate molts.

Prejuvenile Molt

Prejuvenile molt occurs in the nest. There is no information on this molt in Asian Fairy-bluebird.

Preformative Molt

Based on Macaulay Library images (see for example those under Formative Plumage in Plumages section), the Preformative Molt appears to be partial, including body feathering, some (possibly no) inner secondary coverts, and perhaps occasionally 1-3 tertials but no other flight feathers. Timing likely variable based on variable seasonal timing of breeding (see Breeding: Phenology) but likely occurs within the period 1-5 months post fledging, e.g., April-September in nominate populations.

Definitive Prebasic Molt

Complete. Timing likely variable based on variable seasonal timing of breeding (see Breeding: Phenology) but likely begins during the late breeding period and continues for a 1-6 month period, e.g., during February-August in nominate populations. As in most passerines, primaries appear to be replaced distally (from innermost p1 to outermost p10), secondaries appear to be replaced bilaterally from the second tertial (s8) and proximally from the innermost (s1), and rectrices generally appear to be replaced from the central feather (r1) distally on each side of the tail, with some variation in sequence to be expected.

Bill

Bill is entirely black.

Iris and Facial Skin

In adults, iris is brick red or orange red in females, and a more vibrant, bright blood red in males. In juveniles it is brownish becoming reddish-brown during first year. It may be possible that the age of some males in Second Basic Plumage can be inferred by being in definitive plumage (perhaps averaging duller than in older birds) but having a brownish-red to dull red iris. It may also be possible that iris color in adult males becomes more brilliant red during the courting and prebreeding period than during the post-breeding and molting period; study is needed.

Tarsi and Toes

Feet are black.

21.2–25.8 cm; male 56.6–75.7 g, female 52–71.2 g (malayensis), 56 g (crinigera).

Formerly considered conspecific with Philippine Fairy-bluebird (Irena cyanogastra) and, until recently, treated by all global authorities as conspecific with Palawan Fairy-bluebird (Irena tweeddalii). Subspecies andamanica sometimes included in nominate, but differs in having heavier bill; molecular analysis has even suggested it to be a separate species (8 Moltesen, M., M. Irestedt, J. Fjeldså, P. G. P. Ericson, and K. A. Jønsson (2012). Molecular phylogeny of Chloropseidae and Irenidae - cryptic species and biogeography. Molecular Phylogenetics and Evolution 65(3):903–914. Close ). Birds from the northern Indian Subcontinent sometimes separated as subspecies sikkimensis. Body size varies with latitude, outer tropical populations of nominate being largest, equatorial crinigera smallest.

Asian Fairy-bluebird (Asian)

Subspecies vary mainly in color tone of blue parts of adult male, and tail covert shape and length.

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SUBSPECIES

Irena puella puella Scientific name definitions

Distribution

India to Myanmar, Thailand, and Mainland Southeast Asia, including the northern Malay Peninsula.

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SUBSPECIES

Irena puella andamanica Scientific name definitions

Distribution

Andaman Islands

Identification Summary

Subspecies <em>andamanica</em> differs from nominate by heavy bill, broader and marginally deeper than in any other subspecies.

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SUBSPECIES

Irena puella malayensis Scientific name definitions

Distribution

Southern Malay Peninsula.

Identification Summary

Subspecies <em>malayensis</em> resembles nominate, but tail coverts longer.

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SUBSPECIES

Irena puella crinigera Scientific name definitions

Distribution

Sumatra (including islands off west coast), Bangka, Belitung, and Borneo.

Identification Summary

Subspecies criniger is smallest, tail coverts completely encase tail, above and below, to slightly beyond its tip.

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SUBSPECIES

Irena puella turcosa Scientific name definitions

Distribution

Java.

Identification Summary

Subspecies turcosa has tail coverts as previous, but averages slightly larger.

Prior to the recent split of Palwan Fairy-bluebird, the Asian Fairy-bluebird was long considered most closely related to the Philippine Fairy-bluebird (Irena cyanogastra), previously the only other species recognized in the family Irenidae. The estimated time of divergence of about 3 million years ago between the puella and cyanogastra groups in a recent analysis using mitochondrial and nuclear markers (8 Moltesen, M., M. Irestedt, J. Fjeldså, P. G. P. Ericson, and K. A. Jønsson (2012). Molecular phylogeny of Chloropseidae and Irenidae - cryptic species and biogeography. Molecular Phylogenetics and Evolution 65(3):903–914. Close ) supports this close relationship but also is consistent with species status for cyanogastra, as universally treated.

The nominate subspecies has a highly disjunct range, occurring in the lower Western Ghats of west peninsular India from north-central Maharashtra south through southwestern Kerala and western Tamil Nadu; at least formerly also Simlipal Hills of northeastern Odisha (Orissa), northeastern Indian peninsula. The nominate subspecies also occurs throughout the continental south and southeast Asian range of the species, in the lower Himalayas from (at least formerly) eastern Nepal and presently west Sikkim east through northeastern India, northern Myanmar, far western, southern, and southeastern Yunnan, in the south through eastern Bangladesh and the Indian states south of the Brahmaputra, across southeast Asia including the northern Malay Peninsula east throughout Vietnam. Other subspecies occur in the Andaman Islands, southern Malay Peninsula, Sumatra, west Sumatran islands, Bangka and Belitung, Borneo, and Java (where now rare).

Tall tropical to subtropical lowland broadleaf evergreen to semi-evergreen forest, and comparable montane forest; from plains level to 1800 m in Indian Subcontinent (Western Ghats, eastern Himalayan foothills of Bhutan), but generally lower in north (to 1400 in Bhutan (9 Spierenburg, P. (2005). Birds in Bhutan. Status and Distribution. Oriental Bird Club, Bedford, UK. Close ), 1200 m in Sikkim, just 365 m in Nepal (10 Grimmett, R., C. Inskipp, T. Inskipp, and H. S. Baral (2016). Birds of Nepal. Revised edition. Christopher Helm, London, UK. Close ) ); occasionally to 1900 m in Malay Peninsula and on Borneo (11 Mann, C. F. (2008). The Birds of Borneo. An Annotated Checklist. B.O.U. Checklist 23. British Ornithologists’ Union and British Ornithologists’ Club, Peterborough, UK. Close ), but everywhere much commoner below montane ecotone. Avoids deciduous forest, but recorded as visiting low-stature heath-forest in Borneo and degraded forest in parts of Sumatra, as well as oil-palm plantations (11 Mann, C. F. (2008). The Birds of Borneo. An Annotated Checklist. B.O.U. Checklist 23. British Ornithologists’ Union and British Ornithologists’ Club, Peterborough, UK. Close ); emerges from regular habitat into scattered trees of tea estates and shade cover of coffee plantations cut out of forest, occasionally even gardens (11 Mann, C. F. (2008). The Birds of Borneo. An Annotated Checklist. B.O.U. Checklist 23. British Ornithologists’ Union and British Ornithologists’ Club, Peterborough, UK. Close ), presumably where tempted by a flowering or fruiting event.

Essentially resident. Said to be a seasonal (winter) visitor to Coorg Plateau, in Western Ghats (southwestern India), but this may not involve more than local upward movements off neighboring slopes. Records from some tiny islands of Southeast Asian continental shelf presumed to involve only visitors, but no cross-water movements confirmed.

Food Capture and Consumption

Fruits taken while perched or in a flying snatch, mainly in middle stratum and canopy of forest; termites caught in air. Regularly joins mixed-species parties of insectivores hunting among foliage. Raids coffee berries. Observed in flocks of up to ten, but as many as 40 may gather at especially rich food sources (9 Spierenburg, P. (2005). Birds in Bhutan. Status and Distribution. Oriental Bird Club, Bedford, UK. Close , 12 Wells, D.R. (2007). The Birds of the Thai-Malay Peninsula. Vol. 2. Passerines. A. & C. Black, London. Close ).

Major Food Items

Diet mainly fruit, ranging from small berries to figs (Ficus), of which 24 species of the latter genus alone are known in the diet from studies in Peninsular Malaysia, with other species recorded there including Eurycoma longifolia (Simarubaceae), Santiria laevigata (Burseraceae) and Campnospermum auriculatum (Anacardiaceae) (12 Wells, D.R. (2007). The Birds of the Thai-Malay Peninsula. Vol. 2. Passerines. A. & C. Black, London. Close ); also nectar in more seasonal parts of range, but nectar-feeding unrecorded in humid inner tropics; alate termites (Isoptera) also taken. Food of wild nestlings unreported; in captivity, chicks have thrived on a diet exclusively of live insects delivered independently by parents, with fruit offered mainly after fledging.

Vocal Development

No information.

Vocal Array

Asian Fairy-bluebird is a very vocal species, and its loud whistles can be heard from considerable distance. All vocalizations are quite simple and easily identified. Somewhat arbritrarily, the following types can be discerned:

Song. A short simple phrase of whip-like call-type notes alternated with a different phrase which may be slightly longer and may have notes that are richer slurred or whistled, e.g. whit-it!...whee-ee-it...whit-it!...whee-ee-it... or whit!...weeuw...whit!...weeuw...

Whip-like call. One or more loud snapping whistles repeated at regular intervals. The simplest call is a single sharply upslurred liquid whistle whit! (rising from about 2kHz to 4‒5kHz) repeated every few seconds. Equally common is a double note whit!-it! Several more variants exist however, leading to a multitude of different transcriptions in literature.

Bubbling call. Whip-like call note(s) immediately followed by a lower-pitched mellow series of identical upslurred whistles whit-it!-wiwiwiwiwiwiwiwi. Such phrase is usually repeated several times at intervals of several seconds. Again, there is quite some variation, and the initial whip-like notes occasionally are omitted.

Other. Also, a hoarse “chrroachch” croak between pair-members at close quarters, and a thin “wi-wi-wi…” from a female (with bill closed) when resisting being displaced. Flight call has been described as a repeated sharp chichichichik (13 Ali, S., and S. D. Ripley (1996). Handbook of the Birds of India and Pakistan: Together with those of Bangladesh, Nepal, Bhutan and Sri Lanka. Volume 6. 2nd edition. Oxford University Press, Delhi, India. Close ) or chir-rip (12 Wells, D.R. (2007). The Birds of the Thai-Malay Peninsula. Vol. 2. Passerines. A. & C. Black, London. Close ), likely variants of Whip-like call. At take-off, a longer loud salvo of whip-like notes may be given.

Geographic Variation

Has not been studied in detail. Transcriptions of song and calls vary per region (e.g. nominate subspecies “weet weet,” “be-quick,” “what’s it,” “djü-djüt,” “uiiit,” “tui, wit-weet” and “which-ip which-ip which-ip;” versus malayensis “wait” or “whi-it” or “whit, whet, whit), but it is unclear whether differences are at subspecific, geographical or merely at individual level. Genetically fairly distinct subspecies andamanica from the Andaman islands (India) also has a similar voice.

Phenology

Little information. The species is vocal throughout the year, both in the breeding period when in separate pairs and during the non-breeding period when moving around in small groups. It is unknown however if there is some seasonality in Song that can be linked to the breeding period.

Daily Pattern of Vocalizing

Mainly vocal during the morning and again, to a lesser extent, in late afternoon.

Places of Vocalizing

Typically sings or calls from a perch within the canopy of trees in forest.

Sex Differences

Little information. Song is uttered (exclusively?) by male. Whip-like calls are given by both sexes.

Social Content and Presumed Functions of Vocalizations

Little information. Song is typically noticed from single males. Other vocalizations however are usually uttered when small foraging groups move around. Adult males can be particularly conspicuous and noisy in such groups, several individuals calling simultaneously, and it has been suggested this may indicate some lekking behavior (12 Wells, D.R. (2007). The Birds of the Thai-Malay Peninsula. Vol. 2. Passerines. A. & C. Black, London. Close ).

None documented.

Degree of Sociality

Observed in flocks of up to ten, but as many as 40 may gather at especially rich food sources (9 Spierenburg, P. (2005). Birds in Bhutan. Status and Distribution. Oriental Bird Club, Bedford, UK. Close , 12 Wells, D.R. (2007). The Birds of the Thai-Malay Peninsula. Vol. 2. Passerines. A. & C. Black, London. Close ).

Season January–June, peak February–April, in Indian Subcontinent; mainly on gonad condition of specimens, February–June in Peninsular Malaysia (12 Wells, D.R. (2007). The Birds of the Thai-Malay Peninsula. Vol. 2. Passerines. A. & C. Black, London. Close ), December and February–August in northern Borneo (Sabah), and October–May in Java.

Site Characteristics

Nest is placed 2–6 m up on sapling fork or palm frond in shaded understory to lower middle stratum of forest.

Construction Process

Nest is built by the female.

Structure and Composition

Nest is a relatively small (4 cm deep), unusually shallow, flimsy open cup of twigs and bryophytes.

Size

Mean size 28.2 mm × 20.2 mm (nominate).

Color and Surface Texture

Eggs are greenish white or olive-gray with irregular reddish-brown and gray markings.

Clutch Size

Normal clutch two eggs (occasionally three).

In captivity, incubation by female alone, period c. 14 days.

Nestlings tended by one or both parents.

Reported brood parasitism by Common Hawk-Cuckoo (Hierococcyx varius) in southern India thought unlikely on grounds of habitat; requires verification.

Fledging period c. 13 days (extremes 11–18 days).

Not globally threatened (Least Concern). More or less common through most of its extensive range; only locally uncommon or rare, although reckoned to be generally on the decrease throughout. Formerly occurred in Sri Lanka, whence disappeared apparently during late 19th century, and much more recently is suspected to be now extirpated in Nepal (10 Grimmett, R., C. Inskipp, T. Inskipp, and H. S. Baral (2016). Birds of Nepal. Revised edition. Christopher Helm, London, UK. Close ). Massive loss of habitat, and increasing hunting pressure with guns, have led to significant declines in Java (subspecies turcosa) and Sumatra (crinigera); populations in these regions, at least, require re-assessment of status, probably already Near Threatened or even Vulnerable. Removal of large, canopy-cropping fig trees, a common sylvicultural practice even in forest where sustainable logging is carried out, has disproportionately high impact on frugivores reliant on figs as a key food source. Effects of trapping for cagebird trade not known.