Orange-backed Woodpecker Chrysocolaptes validus Scientific name definitions

30 cm; 155–185 g. Male has red forehead, crown and short crest bordered pale orange, orange-brown side of head, darker and browner towards rear; chin and malar area golden-brown; lower nape and hindneck white, bordered brownish-gray, mantle and back feathers extensively tipped yellow to orange, rump deeper orange to red with yellow-olive suffusion, variable brownish barring; uppertail-coverts dark brown to dull orange; scapulars and wing-coverts black-brown; flight-feathers blackish, 3–5 broad rufous-chestnut bars across all feathers, spots on primary coverts; uppertail very dark brown; side of neck, foreneck and most of underbody brown, broad deep red feather tips creating red appearance, narrowly edged yellowish on flanks and lower regions, ventral area gray-brown, dark brown on undertail-coverts and undertail; underwing barred brownish or cinnamon, coverts sometimes paler buffish and barred brown; long bill slightly curved, broad-based, distinct chisel tip, light brown, yellowish lower mandible; iris brownish to orange-red; legs brownish to gray. Female has forehead to nape and crest dark brown, side of head gray-brown, hindneck and upperparts white or off-white, rump brownish, narrow band on side of neck tinged rufous, foreneck and underparts dark gray-brown with obscure paler barring on flanks and belly. Juvenile much as female, but young male usually has some red on crown and often hint of yellow-orange on rump.

There are no similar species within its range.

The Orange-backed Woodpecker is a medium-sized woodpecker with a thin neck and large head with short filamentous crest. Woodpeckers have ten functional primaries (numbered p1 to p10 distally with the outermost, p10, reduced in length), ten secondaries (numbered from outermost s1 to innermost s10 proximally and including 3 tertials, numbered s8–s10 or t1–t3 distally), and 12 rectrices (numbered distally on each side of the tail, from innermost r1 to outermost r6, and with the outermost pair, r6, vestigial or reduced in length). Geographic variation is poorly known and appears to be slight (see Systematics: Subspecies); the following pertains to the widespread subspecies xanthopygius and is based on descriptions in Short (1 Short, L. L. (1982). Woodpeckers of the World. Monograph Series 4, Delaware Museum of Natural History, Greenville, DE, USA. Close ), Wells (2 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ), Winkler and Christie (3 Winkler, H., and D. A. Christie (2002). Family Picidae (woodpeckers). In Handbook of the Birds of the World, Volume 7 (J. del Hoyo, A. Elliott and J. Sargatal, Editors), Lynx Edicions, Barcelona, Spain. pp. 296–555. Close ), Robson (4 Robson, C. (2011). A Guide to the Birds of Southeast Asia. Princeton University Press, Princeton, NJ, USA. Close ), Eaton et al. (5 Eaton, J. A., B. van Balen, N. W. Brickle, and F. E. Rheindt (2016). Birds of the Indonesian Archipelago: Greater Sundas and Wallacea. Lynx Edicions, Barcelona, Spain. Close ), and Treesucon and Limparungpatthanakj (6 Treesucon, U., and W. Limparungpatthanakij (2018). Birds of Thailand. Lynx Edicions, Barcelona, Spain. Close ), along with examination of Macaulay Library images. See Molts for molt and plumage terminology. Sexes differ in all plumages; definitive appearance (full basic wing feathering in females and body plumage in males) appears to be assumed primarily at the Third Basic Plumage, perhaps the Fourth Basic Plumage in some individuals. Seasonal timing of plumages is generally related to peak molting periods which may occur year-round at the population level (2 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ).

Natal Down

Occurs in the nest cavity. Undescribed in the Orange-backed Woodpecker. Most or all woodpecker hatchlings are altricial and naked, with no down developing (1 Short, L. L. (1982). Woodpeckers of the World. Monograph Series 4, Delaware Museum of Natural History, Greenville, DE, USA. Close ).

Juvenile (First Basic) Plumage

Occurs within 1-3 months of fledging. Juvenile Plumage is similar to Definitive Basic Plumage but duller and duskier overall: forehead to nape and crest dusky; sides of head and neck paler grayish; hindneck and upperparts white or off-white; rump brownish; foreneck and underparts gray with obscure paler barring on flanks and belly. Juvenile feathering is filamentous due to lower barb densities. Juvenile flight feathers, especially rectrices, are narrower than basic feathers. See also Bare Parts for age-related and sex-related variation in iris and leg colors.

Juvenile Males reported to sometimes show red tinge to the crest and/or a hint of yellow-orange on rump, these colors lacking in Females of all plumages. Alternatively, it appears that some or all juvenile males may have a more fully red crest and a red wash to the underparts (see below and, e.g., ML469926281 ); study is needed on variation in head plumage of juvenile males.

Formative Plumage

Occurs from three (when fresh) to ten (when worn) months following fledging. Formative Plumage of each sex appears to be duller or duskier than later plumages, especially around the sides of the head. It is best separated from Definitive Basic Plumage by the retention of the juvenile feathers, as in other woodpeckers (7 Pyle, P., and S. N. G. Howell (1995). Flight-feather molt patterns and age in North American woodpeckers. Journal of Field Ornithology 66(4):564–581. Close , 8 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). Some juvenile upperwing secondary coverts, including some to all outer greater coverts, can be retained in some but perhaps not all individuals; these are browner, more worn, and contrast with fresher, replaced inner formative coverts and scapulars. Juvenile outer primary coverts are retained and brownish, and most to all secondaries are juvenile, relatively worn, perhaps contrasting with 1-2 replaced tertials in some birds; otherwise, tertials can become very worn and abraded. See also Bare Parts for age-related and sex-related variation in iris and leg colors; birds in Formative Plumage have duller and grayer or more amber (less reddish) irises than those in Definitive Basic Plumage, and males have duller leg color.

Second Basic Plumage

Occurs during one (when fresh) to 10 (when worn) months following breeding. Second Basic Plumage in the Orange-backed Woodpecker appears to be identifiable in all individuals by retained juvenile primary coverts and possibly secondaries, as in many other woodpeckers (7 Pyle, P., and S. N. G. Howell (1995). Flight-feather molt patterns and age in North American woodpeckers. Journal of Field Ornithology 66(4):564–581. Close , 8 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). Three to seven consecutive medial juvenile primary coverts (among those corresponding to p3–p9) are retained, brown, very abraded, and contrasting with 1–5 consecutive replaced distal feathers (among those corresponding to p6–p10), forming paler panel or badge on upperwing. These contrast with the secondary coverts which, unlike in some or all formative birds, are entirely replaced. Juvenile secondaries, if present, may occur in a block of 1–6 feathers among s1–s6 and include at least s3 and/or s4. See also Bare Parts for age-related and sex-related variation in iris and leg colors; in males, fully bright adult colors may not be reached until Third Basic Plumage (or later) is attained.

Third Basic Plumage

Occurs during one (when fresh) to 10 (when worn) months following breeding. In some woodpeckers, Third Basic Plumage can be identified by having 1–3 adjacent juvenile primary coverts retained, among those corresponding to p5–p7, along with two generations of basic coverts found proximal and distal to these feathers (9 Siegel, R. B., M. W. Tingley, R. L. Wilkerson, C. A. Howell, M. Johnson, and P. Pyle (2016). Age structure of Black-backed Woodpecker populations in burned forests. Auk 133(1):69–78. Close ); examination of Macaulay Library images (see above and, e.g., ML425773541 ) indicates that this occurs in at least some third-basic Orange-backed Woodpeckers. In some woodpecker species, juvenile primary coverts (including that corresponding to p6) may continue to be retained into Fourth Basic Plumage (P. Pyle, unpublished data on genus Sphyrapicus); study is needed to see if this may occur in the Orange-backed Woodpecker.

Definitive Basic Plumage

Occurs during one (when fresh) to ten (when worn) months following breeding. In this species, Definitive Basic Plumage equates to Third Basic Plumage or older.

Female

Forehead to crest and nape dusky brown; sides of head gray-brown, becoming paler or tinged orange toward the malar region; hindneck and back white or off-white, bordered brownish gray, the feathers tipped yellow to orange; rump and uppertail coverts brownish to dull orange with variable darker brownish barring; rectrices black. The scapulars and upperwing coverts are blackish brown, the primary coverts with rufous-orange tips or spots. Primaries and secondaries dark brown with 3–4 broad rufous-chestnut bars across all feathers, resulting in a striking pattern in flight (cf. ML377191551 of a male). A narrow and diffuse pale band down the sides of neck can be whitish or tinged orange; chin can be tinged yellow or orange; foreneck and remaining underparts dark gray-brown with obscure paler barring on flanks and belly. The underwing is dull brown and cinnamon with dark brown tips to the greater and primary coverts (cf. ML377403031 of a male).

In both sexes, Definitive Basic Plumage is typically be characterized by uniformly basic upperwing greater coverts, primary coverts, and secondaries, without molt limits, or with mixed generations of basic feathers in these tracts, the older feathers not contrasting as strongly as between juvenile and basic feathers of Second Basic Plumage (see 7 Pyle, P., and S. N. G. Howell (1995). Flight-feather molt patterns and age in North American woodpeckers. Journal of Field Ornithology 66(4):564–581. Close , 9 Siegel, R. B., M. W. Tingley, R. L. Wilkerson, C. A. Howell, M. Johnson, and P. Pyle (2016). Age structure of Black-backed Woodpecker populations in burned forests. Auk 133(1):69–78. Close , 8 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). See also Bare Parts for age-related and sex-related variation in iris and leg colors, brighter reddish and yellowish, respectively, in this plumage.

Male

Similar to definitive basic female except much brighter and more colorful. Crown and long crest feathers bright red; sides of head, malar region, chin, and throat washed yellow to orange (sometimes bright); back yellow; rump a deeper orange to red with yellow-olive suffusion; uppertail coverts orange; underparts below throat primarily deep scarlet red to red.

Molt and plumage terminology follows Humphrey and Parkes (10 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. (11 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 8 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close and 12 Pyle, P. (2022). Defining moults in migratory birds: a sequence-based approach. Journal of Avian Biology 2022(5):e02958. Close for more information). As in other woodpeckers (8 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). The Orange-backed Woodpecker shows a Complex Basic Strategy (see 11 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 ) with a partial Preformative Molt, an incomplete Second Prebasic Molt, and incomplete to complete Definitive Prebasic Molts but no Prealternate Molts. The following is based primarily on examination of Macaulay Library images.

Prejuvenile Molt

The Prejuvenile Molt occurs in the nest. There is no information on timing of development in the Orange-backed Woodpecker.

Preformative Molt

As in other woodpeckers the Preformative Molt may begin in the nest, before fledging, with replacement of the inner one or two primaries prior to fledging, and molt completing 2-4 months following fedging. The preformative molt appears to be incomplete, including most or all body plumage, primaries, and rectrices, few to some (perhaps occasionally all) proximal secondary coverts and possibly up to 1-3 tertials, but no primary coverts or outer secondaries (see images under Formative Plumage). Primaries are replaced distally (p1 to p10) and rectrices are replaced from r2 distally to r6 on each side of the tail, followed by the central rectrices (r1), a sequence that enables the central rectrices, critical for stability on vertical tree trunks, to be replaced when other rectrices are fresher and stronger (13 Jones, A. W. (2010). Book review: Molt in North American birds. Condor 112(4):862–863. Close ).

Second Prebasic Molt

Incomplete, likely peaking 1-3 months following breeding, as in other woodpeckers. Appears to include all body feathers, upperwing secondary coverts, primaries, and rectrices but not all primary coverts and sometimes not all secondaries. Sequence of primary and rectrix replacement as described under Preformative Molt. As in other woodpeckers (7 Pyle, P., and S. N. G. Howell (1995). Flight-feather molt patterns and age in North American woodpeckers. Journal of Field Ornithology 66(4):564–581. Close , 8 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ), four to eight juvenile primary coverts may be retained in the center of the tract and it appears that 1–4 juvenile secondaries can also be retained, in a block among s1–s5, usually symmetrically in both wings. Replacement of juvenile primary coverts and secondaries occurs in fixed sequence (P. Pyle unpublished data on genus Sphyrapicus): juvenile outer primary coverts are replaced convergently from both ends of the tract, terminating at the coverts corresponding to p6, differing from sequence of the primaries, and juvenile secondaries are replaced distally from s1 and proximally from the tertials (perhaps most often bilaterally from the second tertial, s9), terminating at s3 or s4.

Third Prebasic Molt

Incomplete to complete, likely peaking 1-3 months following breeding, as in other woodpeckers. Some individuals in Third Basic Plumage appear to retain 1–3 juvenile primary coverts corresponding to p5–p7, as documented in other woodpeckers (14 Siegel, R. B., M. W. Tingley, R. L. Wilkerson, C. A. Howell, M. Johnson, and P. Pyle (2016). Age structure of Black-backed Woodpecker populations in burned forests. Auk 133(1):69–78. Close ). See images under Second Basic Plumage.

Definitive Prebasic Molt

Incomplete to complete, likely peaking 1-3 months following breeding but may occur year-round at the population level (15 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ). As in other woodpeckers, all tracts appear to be completely replaced except primary coverts and/or secondaries in some individuals (7 Pyle, P., and S. N. G. Howell (1995). Flight-feather molt patterns and age in North American woodpeckers. Journal of Field Ornithology 66(4):564–581. Close , 9 Siegel, R. B., M. W. Tingley, R. L. Wilkerson, C. A. Howell, M. Johnson, and P. Pyle (2016). Age structure of Black-backed Woodpecker populations in burned forests. Auk 133(1):69–78. Close , 8 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). Sequence of flight-feather replacement as described under Preformative and Second Prebasic Molts. Some basic primary coverts and secondaries appear to be retained (e.g., see images under Definitive Basic Plumage); these can occur throughout these tracts, may or may not occur in consecutive pairs or blocks as are retained juvenile feathers of earlier plumages, and are less often located symmetrically between the wings. Following incomplete molts, replacement within these tracts appears to occur in a Stafflemauser (stepwise)-like manner, whereby convergent molt sequences continue where the previous prebasic molt arrested, while new sequences can commence can commence at each end of each tract (P. Pyle unpublished data on genus Sphyrapicus).

The following is based on descriptions in Wells (2 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ) and Winkler and Christie (3 Winkler, H., and D. A. Christie (2002). Family Picidae (woodpeckers). In Handbook of the Birds of the World, Volume 7 (J. del Hoyo, A. Elliott and J. Sargatal, Editors), Lynx Edicions, Barcelona, Spain. pp. 296–555. Close ), along with examination of Macaulay Library images for age-related variation. See also images under Plumages.

Bill

The bill is stout and chisel-like. At all ages, it appears pale and is primarily brown along the culmen and variably dull to bright yellowish at the tip and along most or all of the lower mandible.

Iris and Facial Skin

The iris appears to vary by age and possibly by sex. In adults it can vary from bright amber to orangish to washed reddish and is generally redder in males than females by age. In nestlings it is dull grayish brown, becoming dull olive in juveniles, dull amber during the first year, and possibly not attaining full adult coloration for three or four years (study needed). It may be possible that the iris becomes brighter and redder in males during courting and prebreeding periods. The orbital ring is grayish in young birds and females or yellowish in adult males.

Tarsi and Toes

Coloration of the legs and feet appears to vary by individual and sex, and to a lesser extent age. They are generally pinkish in nestlings and young juveniles, variably becoming slate or tinged olive or yellow in the first year. In adults, the legs of females continue to vary from slate to dull olive-yellow and those of males from dull olive-yellow to bright yellow (see images of definitive basic males under Plumages and, e.g., ML175552451 ). It may be possible that legs and feet become brighter in males during courting and prebreeding periods. The claws are black to blackish.

In the past, the Orange-backed Woodpecker was commonly included in Chrysocolaptes, but more recently has been placed in a monotypic sister-genus Reinwardtipicus, mainly on grounds of significant differences in plumage colors, behavior and vocalizations; the latest molecular analyses (16 Winkler, H., A. Gamauf, F. Nittinger, and E. Haring (2014). Relationships of Old World woodpeckers (Aves: Picidae) – new insights and taxonomic implications. Annalen des Naturhistorischen Museums in Wien 116:69–86. Close ), however, indicate that this species is genetically so close to Chrysocolaptes that it is better included within it. Subspecies weakly differentiated, with much overlap in features.

Extreme southern Thailand south to Sumatra and Borneo, including Riau Archipelago, Bangka Island, the northern Natuna Islands, and Java.

Primary or secondary evergreen rainforest, coastal vegetation, mature plantations; also along forest edge, and in clear-cuts with single dead trees. Lowlands, extending uncommonly to hilly country throughout range; below 1,000 m in Thailand and Peninsular Malaysia, where most common below 700 m; in lowlands, occasionally in montane habitats to 2,200 m, in Java; common in lowland forests of Borneo, where has also been found to 2,000 m.

Beetle larvae, termites (Isoptera), caterpillars, ants and other insects. Lives in pairs and family parties. Forages in very low (rarely) and middle strata, and in canopy as well. Attacks rotting logs on the ground, also dead stumps, tree trunks and larger branches; even visits thin vines. Pecks and hammers with loud blows to excavate substrate, sometimes spends minutes to excavate at a single site. Often removes bark with lateral strokes, or quickly opens holes in bark. Moves rapidly along trunk and branches. Trees, stumps and logs searched systematically; tends not to move great distances between foraging locations.

Various loud, ringing calls  , e.g., “pit,” singly or in loose irregular series; slow regular “kit kit kit kit kit-it” series of c. 9 elements, terminating with double call rising sharply; other, higher-pitched  , more irregular series may commence with lower note; much faster series of “pit” notes as rattle call; loud rapid “wheet-wheet-wheet-wheet-wheow” or “polleet, polleet” and excited “toweetit-toweetit, cha-cha” also described. Drums weakly, bursts very short.

January–September; insufficient data on regional differences; in northern Borneo (Sabah) nest with young in late March, another nest being built in April. Displays include crest-raising, bill-directing, wing-flicks, wing-spreading and swinging head movements, associated with many vocalizations. Nest-hole excavated c. 5 m up in dead tree. Clutch one or two eggs; incubation and fledging periods not documented; fledglings fed by parents directly, not by regurgitation.

Not globally threatened. Uncommon or scarce in most of its range; rare in Java, but more common in Sumatra and Borneo. Occurs in Khao Nor Chuchi Reserve (Thailand), Taman Negara National Park (Peninsular Malaysia), Gunung Leuser and Way Kambas National Parks (Sumatra), Gunung Gede-Pangrango National Park (Java) and Mount Kinabalu National Park (Borneo).

Chuenchom Hansasuta received a Doctor of Dental Surgery from Chulalongkorn University. During her long and distinguished career in dentistry, she studied and practiced in places such as Thammasat University (Thailand), State University of New York at Buffalo (USA), and University of Connecticut Health Center (USA) and retired in 2020. Chuenchom always had an intense curiosity for birds that over time, evolved into an acute interest in plumages. She has long been active in education and volunteering, becoming chairwoman of The Flyway Foundation and actively engaging and educating the public in the study of birds and their plumages.