Plumages, Molts, and Structure

The following descriptions apply to the nominate subspecies. The other subspecies is described under Systematics: Geographic Variation.

Juvenile

Has dull dusky-green forehead and lacks dark on face. Has paler yellow flanks than adults and narrower rectrices (5 Mees, G. F. (1964). Notes on two small collections of birds from New Guinea. Zoologische Verhandelingen Leiden 66:1–37. Close ).

Adult

Female. Has forehead, lores, and a streak under eye-ring black, extending over anterior part of crown and merging with green nape; eye-ring white, rather narrow, broken at front by black spot; upperparts dark yellowish olive-green, rump yellower; wingtips and tail dusky brownish; throat and underparts yellowish olive-green, becoming almost pure lemon-yellow on center of belly and undertail coverts.

Male. Similar to female, but on average brighter, more yellowish.

Of three specimens of Zosterops fuscicapilla fuscicapilla collected in February, one was molting both primaries and rectrices, another one showed only molt of its forehead feathers, and the third had no signs of molt. Another specimen collected in April and two in October had no signs of molt, while a third specimen from October was molting its primaries (6 Mees, G. F. (1961). A systematic review of the Indo-Australian Zosteropidae (Part II). Zoologische Verhandelingen Leiden 50:1–168. Close ). No further information available.

Bill

Dark gray to blackish, basal half of mandible light gray (7 Gilliard, E. T. and M. LeCroy (1961). Birds of the Victor Emanuel and Hindenburg Mountains, New Guinea. Results of the American Museum of Natural History Expedition to New Guinea in 1954. Bulletin of the American Museum of Natural History 123(1):1–86, pls. 1–17. Close ); orange in juveniles.

Iris

Reddish-brown to dark brown in nominate subspecies (5 Mees, G. F. (1964). Notes on two small collections of birds from New Guinea. Zoologische Verhandelingen Leiden 66:1–37. Close , 7 Gilliard, E. T. and M. LeCroy (1961). Birds of the Victor Emanuel and Hindenburg Mountains, New Guinea. Results of the American Museum of Natural History Expedition to New Guinea in 1954. Bulletin of the American Museum of Natural History 123(1):1–86, pls. 1–17. Close ), silver gray in Zosterops fuscicapilla crookshanki (4 Pratt, T. K., and B. M. Beehler (2015) Birds of New Guinea. Second edition. Princeton University Press, Princeton, New Jersey, USA. Close ).

Tarsi and Toes

Tarsi and toes are gray (7 Gilliard, E. T. and M. LeCroy (1961). Birds of the Victor Emanuel and Hindenburg Mountains, New Guinea. Results of the American Museum of Natural History Expedition to New Guinea in 1954. Bulletin of the American Museum of Natural History 123(1):1–86, pls. 1–17. Close ).

Linear Measurements

Wing length

Zosterops fuscicapilla fuscicapilla: male 61 mm (n = 1) (7 Gilliard, E. T. and M. LeCroy (1961). Birds of the Victor Emanuel and Hindenburg Mountains, New Guinea. Results of the American Museum of Natural History Expedition to New Guinea in 1954. Bulletin of the American Museum of Natural History 123(1):1–86, pls. 1–17. Close ); male 60.5 mm (range 59–62, n = 10), female 60 mm (range 58–62, n = 10) (8 Rand, A. L. (1942). Results of the Archbold Expeditions. No. 43. Birds of the 1938-1939 New Guinea expedition. Bulletin of the American Museum of Natural History 79(7):425–516. Close ); both sexes 58.62 mm (range 57–61, n = 17) (6 Mees, G. F. (1961). A systematic review of the Indo-Australian Zosteropidae (Part II). Zoologische Verhandelingen Leiden 50:1–168. Close ).

Zosterops fuscicapilla crookshanki: female 60.5 mm ± 0 SD (n = 2) (9 Mayr, E., and A. L. Rand (1935). Results of the Archbold Expeditions. 6. Twenty four apparently undescribed birds from New Guinea and the D’Entrecasteaux Archipelago. American Museum Novitates 814:1–17. Close ).

Tail Length

Zosterops fuscicapilla fuscicapilla: male 41 mm (n = 1) (7 Gilliard, E. T. and M. LeCroy (1961). Birds of the Victor Emanuel and Hindenburg Mountains, New Guinea. Results of the American Museum of Natural History Expedition to New Guinea in 1954. Bulletin of the American Museum of Natural History 123(1):1–86, pls. 1–17. Close ); both sexes 36.81 mm (range 35–39.5, n = 17) (6 Mees, G. F. (1961). A systematic review of the Indo-Australian Zosteropidae (Part II). Zoologische Verhandelingen Leiden 50:1–168. Close ).

Zosterops fuscicapilla crookshanki: female 42.25 mm ± 1.77 SD (n = 2) (range: 41–43.5, n = 2) (9 Mayr, E., and A. L. Rand (1935). Results of the Archbold Expeditions. 6. Twenty four apparently undescribed birds from New Guinea and the D’Entrecasteaux Archipelago. American Museum Novitates 814:1–17. Close ).

Tarsus Length

Zosterops fuscicapilla crookshanki: female 17.25 mm ± 0.35 SD (range: 17–17.5, n = 2) (9 Mayr, E., and A. L. Rand (1935). Results of the Archbold Expeditions. 6. Twenty four apparently undescribed birds from New Guinea and the D’Entrecasteaux Archipelago. American Museum Novitates 814:1–17. Close ); both sexes 16.30 mm (range 16–17.5, n = 15) (6 Mees, G. F. (1961). A systematic review of the Indo-Australian Zosteropidae (Part II). Zoologische Verhandelingen Leiden 50:1–168. Close ).

Mass

Zosterops fuscicapilla fuscicapilla: male 11.2 g (n = 1) (7 Gilliard, E. T. and M. LeCroy (1961). Birds of the Victor Emanuel and Hindenburg Mountains, New Guinea. Results of the American Museum of Natural History Expedition to New Guinea in 1954. Bulletin of the American Museum of Natural History 123(1):1–86, pls. 1–17. Close ); male 10.8 g ± 0.29 SD (range 10.5–11, n = 3) (10 Mayr, E., and R. Meyer de Schauensee (1939). Zoological results of the Denison-Crockett expedition to the South Pacific for the Academy of Natural Sciences of Philadelphia 1937-1938. Part 4. Birds from northwest New Guinea. Proceedings of the Academy of Natural Sciences of Philadelphia 91:97–144. Close ).