Olive-backed Woodpecker Gecinulus rafflesii Scientific name definitions

c. 26–28 cm; 87–119 g (rafflesii), 76–84 g (dulitense). Male  has red forehead, crown and crest, black and white stripes on side of head and down side of neck, buffy-yellow lores, cinnamon to yellowish or rusty malar area (sometimes red feather tips); chin and upper throat buffish cinnamon, yellowish or rusty-yellow; hindneck and uppermost mantle black, rest of upperparts dark olive-green with bronzy or yellowish feather tips, rump and uppertail-coverts occasionally with orange tips (rarely, dull reddish), bronzy or yellowish olive-green wing-coverts; brownish-black flight-feathers, yellow-green outer webs of secondaries, inner webs with white spots; uppertail black; olive to grayish olive below, often with rusty staining, flanks usually with white spots, sometimes absent; underwing dark brownish, spotted white; fairly long bill chisel-tipped, culmen slightly curved, narrow across nostrils, gray to blackish; iris dark red-brown; legs blue-gray, greenish gray (1 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ) or gray, only three toes. Female  has red on head replaced by black, forehead and crown often more olive, crest slightly smaller than male’s. Juvenile duller, grayer, male with crown blackish or dark olive, red only on crest or also a few scattered spots on forehead, female as adult but crown more olive.

The Common Flameback (Dinopium javanense) has a brownish-yellow, not olive, back. In addition, the head of the Olive-backed Woodpecker seems proportionally larger, relative to the body.

The Olive-backed Woodpecker is a very small, compact woodpecker with thin neck and large head with prominent 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 three 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). In several Macaulay Library images (e.g., ML423242081 , ML183758331 , and ML559475581 ) the r5s appear to lay above the other rectrices are are angled upwards; study is needed on this. Geographic variation in poorly known (see Systematics: Systematics History); the following pertains to both purported subspecies and is based on descriptions in Short (2 Short, L. L. (1982). Woodpeckers of the World. Monograph Series 4, Delaware Museum of Natural History, Greenville, DE, USA. Close ), Wells (1 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 feathering) appears to be assumed primarily at the Third Basic Plumage. Seasonal timing of plumages is generally related to peak molting periods in April-November (1 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ) but plumages could be in various fresh and worn states at other times of the year; study needed.

Natal Down

Occurs in the nest cavity. Undescribed in the Olive-backed Woodpecker. Most or all woodpecker hatchlings are altricial and naked, with no down developing (2 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 during within 1-3 months of fledging, perhaps primarily in July-October. Juvenile Plumage is similar to Definitive Basic Plumage but the dark areas are duller and more brownish or grayish. Juvenile Females are similar to later plumages, with dark crowns and crests, whereas juvenile Males differ from later plumages in having a blackish or dark olive crown (sometimes with a few scattered red feather tips) and orange-red crest feathers. Juvenile body feathering, including crest feathers, is weaker and more filamentous due to lower barb densities than in later plumages, and juvenile flight feathers, especially rectrices, are narrower than basic feathers. The crest average shorter and rounder in juveniles than in older birds. The juvenile outer primary (p10) is often longer and more rounded than in later feather generations, extending farther beyond the primary coverts, but specific details for the Olive-backed Woodpecker are needed. In addition, the iris appears to be browner in juveniles than in older birds (see Bare Parts) as is the case for many other woodpecker species.

Formative Plumage

Occurs during 3-10 months following fledging, perhaps primarily in August (when fresh) to June (when worn). Formative Plumage of each sex is separable 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, appear to be retained in at least some individuals; these are grayer, 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. In addition, the iris color likely changes from brown to brown tinged reddish while in Formative Plumage (see Bare Parts).

Second Basic Plumage

Second Basic Plumage is undocumented in the Olive-backed Woodpecker but likely can be identified in some to 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) may be 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. 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 ); however, this appears to occur primarily in larger or northern species that replace fewer feathers per year, and might not be expected in the Olive-backed Woodpecker.

Definitive Basic Plumage

Occurs during 1-10 months following breeding, perhaps primarily in September (when fresh) to July (when worn).

Female

Crown, full crest, nape, and sides of head black with prominent widening postocular subauricular stripes above and below a broad white bar extending from the eye to the sides of the nape; lores, base of subauricular stripe, chin, and throat yellow, the throat separated from the subauricular by a distinct black malar stripe. Upperparts, upperwing coverts, and tertials olive when fresh to yellowish olive when worn. Rectrices, primary coverts, and primaries black, most primaries with white spots along the outer web and some outer primaries (p7-p9) with white to pale tips, broader on the inner web (see ML559475581 ); secondaries with dusky inner webs and olive outer webs, appearing uniformly olive on the closed upper wing. Underparts below throat blackish gray or tinged olive, often with white flecking to the sides and flanks.

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 ). In addition, the iris is a deeper brown tinged dark reddish in older (see Bare Parts).

Male

Similar to definitive basic female except that the crown and long crest feathers are bright 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 Olive-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, with timing based on information in Wells (13 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ).

Prejuvenile Molt

The Prejuvenile Molt occurs in the nest, perhaps primarily in April-August. There is no information on timing of development in Olive-backed Woodpecker.

Preformative Molt

May occur primarily in May-October. 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, some to perhaps 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 (14 Jones, A. W. (2010). Book review: Molt in North American birds. Condor 112(4):862–863. Close ).

Second Prebasic Molt

May occur primarily in May-November. Likely incomplete and peaking 1-3 months following breeding, as in other woodpeckers; study is needed on variation in the extent of this molt in this species. Appears to include all body feathers, upperwing secondary coverts, primaries, and rectrices but not all primary coverts and perhaps 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 1–3 juvenile secondaries can also be retained, in a block among s2–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.

Definitive Prebasic Molt

Incomplete to complete, likely peaking 1-3 months following breeding, primarily in April-November among all populations (13 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 below and 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 at each end of each tract (P. Pyle unpublished data on genus Sphyrapicus).

The following is based on descriptions in Wells (1 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.

Bill

The bill is stout and chisel-like and primarily slate blue to grayish, the tip becoming gradually blacker.

Iris and Facial Skin

The iris appears to vary by age, as in most other woodpeckers (cf.8 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ), from duller brownish or tinged grayish in nestlings and juveniles to deeper brown tinged dark reddish adults. The orbital ring is grayish.

Tarsi and Toes

The legs and feet are a dingy slate gray or tinged greenish with blackish claws.

Original description previously attributed to Vigors and Horsfield, but Vigors alone was the author (15 Bruce, M.D. (2003). Systematic notes on Asian birds. 40. The authorship of the new bird names proposed in the “Memoir of the Life of Raffles” by his widow, Lady Sophia Raffles (1830). Zool. Verhand. Leiden 344: 111–115. Close ). Individual variation considerable, and subspecies poorly marked, differing only in size; described subspecies peninsulare (Malacca, in Peninsular Malaysia) considered synonymous with nominate.

Southern Myanmar (southern Tenasserim) and peninsular Thailand south to Sumatra, including Bangka Island, and Borneo.

Dense, wet evergreen forest, including swamp-forest, mangroves; avoids secondary growth and clearings. Mainly lowlands and hills, to 1,200 m; locally to 1,600 m in Borneo.

Resident.

Ants, termites (Isoptera), and especially ant pupae. Singly and in pairs. Forages at low and middle heights, below 10 m, on fallen logs, at bases of trees and saplings, and to tops of lower saplings and snags; also on branches of lower crown. Rarely, ventures outside forest to visit dead stumps. Main technique is gleaning; pecks occasionally, more frequently than the Common Flameback (Dinopium javanense). Moves slowly and continuously, pausing only briefly.

Single “chak” note; also rapid series of loud notes in two versions, slow “chakchakchak-chak,” 6–34 notes, varies in rate and pitch, sometimes single notes appended, given when pair-members interact, and faster, more regular, with 10–50 notes, probably as territorial call; low “ch-wee, ch-wee, chwee” calls during encounters and sometimes associated with head-swinging; soft, even trilling “ti-i-i-i-i,” and squeaky “tiririt” also described. Not known to drum, but incubating birds tap in soft regular bursts of 10–12 strokes.

March–May; apparently October in Borneo. Displays include crest-raising, bowing movements, head-swinging; courtship feeding by male. Nest excavated by both sexes, at 4.5–9 m up in tree, even in live wood. Clutch size not recorded; both sexes incubate. No other information.

Not globally threatened. Currently considered Near Threatened. Scarce to uncommon throughout its range; perhaps somewhat commoner in parts of Borneo, although few records from eastern Kalimantan (16 Eames, J.C. (2005). A preliminary ornithological assessment and conservation evaluation of the PT Daisy logging concession, Berau district, East Kalimantan, Indonesia. Forktail 21: 51–60. Close ); extinct in Singapore. Occurs in several protected areas, e.g., Kaeng Krachan National Park (Thailand) and Gunung Mulu National Park, Batu Punggul Forest Reserve, and Danum Valley Conservation Area (Borneo). Within this species’ range, huge areas of lowland forest have already been destroyed; although it appears to remain in reasonable numbers in the higher parts, additional habitat loss could easily pose a major threat.

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.