Scaly-breasted Kingfisher Actenoides princeps Scientific name definitions

Also known as the Regent Kingfisher or Bar-headed Wood Kingfisher, or simply as the Scaly Kingfisher, this rather shy and stolid-looking species is endemic to Sulawesi, where it is rather widespread but decidedly uncommon. Three reasonably well-marked subspecies have been described, which are sometimes considered to represent two different species, and a fourth, presumably closely related taxon, known to date from just a single sight record in eastern Sulawesi, might yet be added to that list. Mainly brown above with a deep blue head, marked by either a buffy supraloral spot (in the male), or a buffy supercilium and moustachial (in females), this kingfisher has generally pale underparts vermiculated or barred dark, and a fairly long, deep-based, and colorful bill. Its basic biology is virtually unknown.

The mainly lowland Green-backed Kingfisher (A. monachus) is the only real identification issue, as both have blue heads and rufous collars, and in females a buffy forehead; however, the present species is distinguished by its buff-scalloped dark brown back in all plumages (versus uniform dark green in Green-backed) and underparts pattern (Green-backed is dark rufous below). Green-backed Kingfisher always has a bright red bill, whereas in Scaly-breasted Kingfisher the bill color is variable, red in northwest and central Sulawesi, more or less horn-colored in the northeast of the island, and brown and orange in southeast Sulawesi.

Unlikely to be confused with other kingfishers on Sulawesi.

Nestling

Unknown.

Juvenile

Recalls the adult female, but has more extensive and broader rufous barring on the back and wing-coverts, more narrowly barred underparts, an extensive buffy forehead, and the bill is dark brown with a pale tip.

Adult male

Has a dark purple-blue head, darkest on the lores to forehead, a buffy supraloral spot, a yellowish-buff to rufous-tinged collar, and dark brown mantle, back, wing-coverts, and rump with buff scallops, formed by narrow pale tips and narrow black subterminal bands to the feathers. The tail, primaries, and secondaries are also dark brown. The chin and throat are white. Pale underparts with fine barring . The underwing-coverts are rufous-buff, with dusky barring.

Adult female

Similar to the adult male, but most obviously distinguished by having a buffy eyebrow (from the bill base to the rear ear-coverts) and moustachial, and more heavily barred/vermiculated dark on the white underparts, especially the flanks.

No information.

Bill

Yellowish brown (in nominate, see Subspecies for racial variation).

Iris

Dark brown.

Legs and Feet

Yellowish brown.

Linear Measurements

Overall length 24–25 cm (1 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 ).

Linear measurements (in mm, from Fry et al. 2 Fry, C. H., K. Fry, and A. Harris (1992). Kingfishers, Bee-eaters and Rollers. Christopher Helm, London, UK. Close , where sample sizes are not reported):

Mass

105 g (one female) (3 Riley, J., and J. Mole (2001). The birds of Gunung Ambang Nature Reserve, North Sulawesi, Indonesia. Forktail 17:57–66. Close ).

Editor's Note: This article requires further editing work to merge existing content into the appropriate Subspecies sections. Please bear with us while this update takes place.

Occasionally placed in a separate genus Monachalcyon (4 Salvin, O., and E. Hartert (1892). Catalogue of the Birds in the British Museum. Volume 16. Trustees of the British Museum (Natural History), London, UK. Close , 5 Stresemann, E. (1931). Vorläufiges über die ornithologischen Ergebnisse der Expedition Heinrich 1930-1931. Ornithologische Monatsberichte 39:7–14, 44–47, 77–85, 102–105, 167–171. Close , 6 Stresemann, E. (1932). Vorläufiges über die Ornithologischer Ergebnisse der Expedition Heinrich 1930-32. VII. Zur Ornithologie von Südost Celebes. Ornithologische Monatsberichte 40:104–115. Close ), or in a much-expanded Halcyon (7 Peters, J. L. (1945) Check-list of birds of the world. Volume 5. Museum of Comparative Zoology, Harvard University Press, Cambridge, MA, USA. Close ). The three subspecies have been suggested to represent two species-level taxa, with the nominate race and A. p. erythrorhamphus being split from A. p. regalis (8 del Hoyo, J., and N. J. Collar (2014). HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1. Non-passerines. Lynx Edicions, Barcelona, Spain. Close ), while recent observations of a currently unidentified kingfisher in eastern Sulawesi might even pertain to a third species in the complex (9 Rheindt, F. E., D. M. Prawiradilaga, Suparno, H. Ashari, and P. R. Wilton (2014). New and significant island records, range extensions and elevational extensions of birds in eastern Sulawesi, its nearby satellites, and Ternate. Treubia 41:61–90. Close ). Eaton et al. (1 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 ) also speculated that multiple species might be involved.

Variation centers on the head pattern, upperparts pattern, underparts pattern, and bill color.

Three subspecies recognized.

A. p. princeps (Reichenbach, 1851)—northeast Sulawesi. Described under Plumages.

A. p. erythrorhamphus (Stresemann, 1931)—northwest, central, and southwest Sulawesi. Differs from the nominate in having a red bill, and a more rufous and darker collar, a paler, more azure-blue crown and face, and more rufous on the sides of the underparts (10 White, C. M. N., and M. D. Bruce (1986). The Birds of Wallacea (Sulawesi, the Moluccas & Lesser Sunda Islands, Indonesia). An Annotated Check-list. British Ornithologists’ Union Check-list 7. British Ornithologists’ Union, London, UK. Close , 8 del Hoyo, J., and N. J. Collar (2014). HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1. Non-passerines. Lynx Edicions, Barcelona, Spain. Close ). There is some evidence of intergradation with the nominate race in that birds from the Matinan Mts, in northwest Sulawesi, have the bill tinged dusky (10 White, C. M. N., and M. D. Bruce (1986). The Birds of Wallacea (Sulawesi, the Moluccas & Lesser Sunda Islands, Indonesia). An Annotated Check-list. British Ornithologists’ Union Check-list 7. British Ornithologists’ Union, London, UK. Close ).

A. p. regalis Stresemann, 1932—southeast Sulawesi. From the evidence of the only known two specimens (one an adult female, the other a near-adult male), differs from both other species on account of its black (versus dark blue) forecrown and face (malar area to ear-coverts), dull blue-green (versus dark blue) mid-crown to hindcrown; lack of buff barring on the mantle, back, and scapulars; and much stronger buff underparts (at least in female) (8 del Hoyo, J., and N. J. Collar (2014). HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1. Non-passerines. Lynx Edicions, Barcelona, Spain. Close ).

A kingfisher observed at c. 2,100 m on Gunung Tumpu, in eastern Sulawesi, had a deep blue cap, a mostly bright red bill becoming more yellowish at the tip, a white throat, unmarked intense orange underparts, reaching onto the nape in the form of a collar (somewhat like Green-backed Kingfisher A. monachus), a conspicuous round buff loral patch, an earth-brown back scaled off-white, and probably an all-brown tail; unfortunately, it proved impossible to document the record, but the bird was presumed to represent a new taxon, colloquially referred to as Tumpu Kingfisher (1 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 tentatively ascribed to the present species complex, although if this suite of characters can be confirmed in future as belonging to a population of kingfishers in the eastern mountains of Sulawesi, then it would seem highly likely to represent a new species (9 Rheindt, F. E., D. M. Prawiradilaga, Suparno, H. Ashari, and P. R. Wilton (2014). New and significant island records, range extensions and elevational extensions of birds in eastern Sulawesi, its nearby satellites, and Ternate. Treubia 41:61–90. Close ).

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EBIRD GROUP (POLYTYPIC)

Scaly-breasted Kingfisher (Scaly-breasted) Actenoides princeps princeps/erythrorhamphus

Available illustrations of subspecies in this group

• eBird map
• 64 photos
• 4 recordings

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SUBSPECIES

Actenoides princeps princeps Scientific name definitions

Distribution

NE Sulawesi.

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SUBSPECIES

Actenoides princeps erythrorhamphus Scientific name definitions

Distribution

NW, C and SW Sulawesi.

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EBIRD GROUP (MONOTYPIC)

Scaly-breasted Kingfisher (Plain-backed) Actenoides princeps regalis Scientific name definitions

• eBird map
• 0 photos
• 0 recordings

Distribution

SE Sulawesi.

Believed to be closely related to the Philippine endemic Spotted Kingfisher (A. lindsayi), which in turn is considered to form a superspecies with another Philippine endemic Blue-capped Kingfisher (A. hombroni), and the South-East Asian Rufous-collared Kingfisher (A. concretus) (11 Fry, C. H. (1980). The evolutionary biology of kingfishers (Alcedinidae). Living Bird 18:113–160. Close ).

The species’ scientific name, princeps, honors Jules Laurent Lucien, later Charles Lucien Jules Laurent, the second Prince of Canino and Musignano, and Prince Bonaparte (1803–1857), the French ornithologist, taxonomist, and collector.

Nothing known.

Distributed virtually throughout the island of Sulawesi, although there are virtually no records from the southeast peninsula.

Primary and tall secondary hill and montane forest, mainly at 900–2,000 m, occasionally as low as 250 m (10 White, C. M. N., and M. D. Bruce (1986). The Birds of Wallacea (Sulawesi, the Moluccas & Lesser Sunda Islands, Indonesia). An Annotated Check-list. British Ornithologists’ Union Check-list 7. British Ornithologists’ Union, London, UK. Close ). The sole known locality for the race regalis was at 2,000 m (10 White, C. M. N., and M. D. Bruce (1986). The Birds of Wallacea (Sulawesi, the Moluccas & Lesser Sunda Islands, Indonesia). An Annotated Check-list. British Ornithologists’ Union Check-list 7. British Ornithologists’ Union, London, UK. Close ). Observed chiefly in the lower stratum of forest (10 White, C. M. N., and M. D. Bruce (1986). The Birds of Wallacea (Sulawesi, the Moluccas & Lesser Sunda Islands, Indonesia). An Annotated Check-list. British Ornithologists’ Union Check-list 7. British Ornithologists’ Union, London, UK. Close ), but also seen in the lower canopy and midstorey. Largely separated elevationally from Green-backed Kingfisher (A. monachus), which occurs at lower elevations, although some overlap exists.

Presumably sedentary.

Few data available. Insects, beetles (Coleoptera), also cicada (Cicadidae) nymphs, and small lizards (12 Riley, J., and J. Mole (2001). The birds of Gunung Ambang Nature Reserve, North Sulawesi, Indonesia. Forktail 17:57–66. Close ) are all known to be taken.

Generally calls before and at dawn (2 Fry, C. H., K. Fry, and A. Harris (1992). Kingfishers, Bee-eaters and Rollers. Christopher Helm, London, UK. Close ). The song, which can be given as a duet, is a single mournful whistle  that rises gradually and then falls, and may be given repeatedly, rendered ssweeee and lasts c. 1.5 seconds (1 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 ); also a series of soft mournful whistles  , initially rolling, then rising in pitch, before ultimately falling away. Dawn song of race erythrorhamphus  is said to sound flatter, with less obvious rising and falling elements, although it retains the generally mournful quality. Agitated calls include an excited er-hoo, er-hoo, er-hoo... (1 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 ). The voice of the race regalis is apparently unknown.

Virtually nothing is known. Season said to be July–August (10 White, C. M. N., and M. D. Bruce (1986). The Birds of Wallacea (Sulawesi, the Moluccas & Lesser Sunda Islands, Indonesia). An Annotated Check-list. British Ornithologists’ Union Check-list 7. British Ornithologists’ Union, London, UK. Close ). The species is believed to excavate a nest-tunnel in an earth bank (13 Watling, D. (1983). Ornithological notes from Sulawesi. Emu 83(4):247–261. Close ); one clutch of four eggs was collected in the 19th century (2 Fry, C. H., K. Fry, and A. Harris (1992). Kingfishers, Bee-eaters and Rollers. Christopher Helm, London, UK. Close ). No further information.

Because the three races are treated as two species by BirdLife International, their conservation status is evaluated separately on the IUCN list, and it consequently makes sense to discuss each taxon separately below. Prior to the analysis of del Hoyo and Collar (14 del Hoyo, J., and N. J. Collar (2016). Handbook of the Birds of the World and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2. Lynx Edicions, Barcelona, Spain. Close ), BirdLife considered the single species to be Least Concern. The species is confined to the Sulawesi Endemic Bird Area (15 Stattersfield, A. J., M. J. Crosby, A. J. Long, and D. C. Wege (1998). Endemic Bird Areas of the World: Priorities for Biodiversity Conservation. BirdLife Conservation Series 7. BirdLife International, Cambridge, UK. Close ). Forest destruction on Sulawesi has been extensive in recent decades, being estimated at 10.8% between 2000 and 2010, driven by clearance for transmigration settlements, agricultural and infrastructural development, and industrial-scale logging. Most primary forest below 1,000 m (i.e. below the elevational range of this species) has been reduced to remnants, and such losses are likely to now be extending higher into hill and montane forest. There is an urgent requirement to conduct intensive surveys of known and potential sites for this species in order to determine abundance and population trends, and to understand its level of tolerance of secondary habitats, as well as to ensure the protection of existing forest reserves.

A. p. princeps (Scaly-breasted Kingisher) and A. p. erythrorhamphus (Lore Lindu Kingfisher) Currently considered Near Threatened. Reportedly uncommon, but this may reflect its shy, inconspicuous habits. No estimates of overall population, but range calculated to encompass c. 101,000 km². Present in Dumoga-Bone National Park (16 Rozendaal, F., and R. W. R. J. Dekker (1989). Annotated checklist of the birds of the Dumoga-Bone National Park, North Sulawesi. Kukila 4(3–4):85–109. Close ), Lore Lindu National Park, Gunung Ambang Nature Reserve (12 Riley, J., and J. Mole (2001). The birds of Gunung Ambang Nature Reserve, North Sulawesi, Indonesia. Forktail 17:57–66. Close ), and in Tangkoko Duasudara Nature Reserve (17 Anon. (1996). Kingfisher study at Tangkoko-Duasudara Nature Reserve, North Sulawesi. Bulletin of the Oriental Bird Club 24:10–11. Close ).

A. p. regalis (Plain-backed Kingfisher or Regal Kingfisher) VULNERABLE. Very poorly known, with apparently just two specimens in museum collections (one adult female and one immature male), and its overall population is thought to probably number fewer than 10,000 mature individuals, with BirdLife currently estimating it at between 2,500 and 9,999 mature individuals, while acknowledging that the true figure might be lower than this. Overall range estimated at just 19,200 km².