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| Ducula tawitawi Halley, 2026 |
Abstract
Only three specimens of the Pink-bellied Imperial Pigeon Ducula poliocephala (G. R. Gray) are available from the isolated population on Tawi-Tawi Island, in the Sulu Archipelago, Philippines, and all have white (vs. brown) throats—a character shared with the closely related White-bellied Imperial Pigeon D. forsteni (Bonaparte). Two adults collected on Tawi-Tawi by the Menage Expedition, in 1891, are preserved in the National Museum of Natural History, Smithsonian Institution, Washington, DC. They bear archival labels with a nomen nudum (albigularis) indicating that the collectors initially considered them to be undescribed—because of the white throats—yet did not publish a description. A third white-throated specimen, collected in 1971 and preserved in the Delaware Museum of Nature & Science, Wilmington, confirms the morphological distinctiveness of the Tawi-Tawi population. Audio recordings from the 1990s further reveal that the Tawi-Tawi population is vocally distinct from D. poliocephala and D. forsteni. Based on its unique morphology and voice, I describe the ‘Tawi-Tawi Imperial Pigeon’ as a new species. It is endemic to the shrinking forests of Tawi-Tawi and faces an imminent risk of extinction.
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| Historic specimens of the ‘Tawi-Tawi Imperial Pigeon’Ducula tawitawi sp. nov. collected by Bourns and Worcester at Tataan (modern Tarawaken) during the Menage Expedition and held at the National Museum of Natural History, Smithsonian Institution, Washington, DC: (top left) USNM 314700, 21 October 1891; (bottom left) USNM 314701, 19 October 1891; the pale greenish-grey stains on the chins of these specimens were evidently caused by post-mortem fat migration (Matthew R. Halley; reproduced courtesy of the Bird Division, National Museum of Natural History, Smithsonian Institution, Washington, DC) |
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| Ducula tawitawi sp. nov. (left) Three views of DMNH 14999 and (right) its label and entry in the Delaware Museum of Nature & Science, Wilmington, ledger; the specimen was identified (apparently by duPont, see text) as ‘Ducula poliocephala nobilis’ when it was catalogued in 1972 (Matthew R. Halley) |
Ducula tawitawi sp. nov.
Tawi-Tawi Imperial Pigeon
Diagnosis.—D. tawitawi has the pink belly of D. poliocephala (unlike D. forsteni) but the white throat of D. forsteni (unlike D. poliocephala). Its courtship or advertising song has a unique acoustic structure consisting of a low-amplitude buzz or ‘rattle’ followed by more notes (5–8) compressed into a shorter time interval, resulting in a higher tempo, than D. poliocephala and D. forsteni.
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| Geographic variation in throat colour in the Pink-bellied Imperial Pigeon Ducula [poliocephala] complex, as demonstrated by adult males held in the Delaware Museum of Nature & Science, Wilmington: (A) DMNH 4501: Samar, May 1970; (B) DMNH 66314: Sibuyan, June 1973; (C) DMNH 1701: Mindanao, June 1961; (D) DMNH 14999: Tawi-Tawi, December 1971; (E) DMNH 10576: Mindoro, March 1971; (F) DMNH 66318: Marinduque, April 1972; (G) DMNH 3501: Luzon, March 1969 (Matthew R. Halley) |
Matthew R. Halley. 2026. A New Species of Imperial Pigeon (Columbidae: Ducula) from Tawi-Tawi, Philippines. Bulletin of the British Ornithologists’ Club. 146(3); 295-310 DOI: doi.org/10.25226/bboc.v146i3.2026.a7 (2 September 2026)
