Zosterops conspicillata saypani Dubois
Bridled White-eye
Zosterops conspicillata Saypani Dubois, Syn. Avium, 1, 1902, p. 711. (Type locality, Saypan.)
Zosterops conspicillata Oustalet (part), Nouv. Arch. Mus. Hist. Nat. Paris, (3), 7, 1895, p. 205 (Saypan); Hartert (part), Novit. Zool., 5, 1898, p. 57 (Saipan); Finsch (part), Das Tierreich, no. 15, 1901, p. 37 (Saipan); Matschie (part), Journ. f. Ornith., 1901, pp. 112, 113 (Saipan); Prowazek, Die deutschen Marianen, 1913, p. 101 (Saipan); Takatsukasa and Kuroda (part), Tori, 1, 1915, p. 64 (Marianne = Saipan).
Zosterops conspicillata var. saypani Snouckaert, Alauda, (2), 3, 1931, p. 22 (Saypan).
Zosterops conspicillatus Kuroda (part), in Momiyama, Birds Micronesia, 1922; p. 76 (Saipan).
Zosterops saipani Mathews, Syst. Avium Australasianarum, 2, 1930, p. 706 (Saipan).
Zosterops conspicillata saipani Stresemann, Mitt. Zool. Mus. Berlin, 17, 1931, p. 227 (Saipan); Hand-list Japanese Birds, rev., 1932, p. 173 (Saipan, Tinian); Hand-list Japanese Birds, 3d ed., 1942, p. 192 (Saipan, Tinian); Mayr, Amer. Mus. Novit., no. 1269, 1944, p. 7 (Tinian, Saipan); idem, Birds Southwest Pacific, 1945, p. 299 (Saipan, Tinian); Downs, Trans. Kansas Acad. Sci., 49, 1946, p. 104 (Tinian); Stott, Auk, 64, 1947, p. 527 (Saipan); Baker, Smithson, Misc. Coll., vol. 107, no. 15, 1948, p. 73 (Saipan, Tinian).
Zosterops conspicillatus saipani Yamashina, Tori, 7, 1932, p. 398 (Tinian).
Geographic range.—Micronesia: Mariana Islands—Tinian, Saipan.
Characters.—Adult: Resembles Z. c. conspicillata, but slightly smaller with fronto-loral band more greenish yellow; auriculars olivaceous; orbital ring narrower; upper parts brighter olive; underparts pale yellowish-white; bill darker. Birds from Saipan resemble closely birds from Tinian, but upper parts may be slightly brighter and underparts slightly more yellowish; iris chestnut.
Measurements.—Measurements are listed in [table 50]. Twenty-three birds from Tinian measure: wing, 51 (50-53); tail, 38 (35-41); full culmen, 12.0 (12.0-13.0); tarsus, 18 (17-18); six birds from Saipan measure: wing, 54 (52-55); tail, 37 (35-39); full culmen, 13.0 (13.0-15.0); tarsus, 18 (17-19). Birds from Saipan are slightly larger than birds from Tinian.
Specimens examined.—Total number, 33 (18 males, 13 females, 2 unsexed), as follows: Mariana Islands, USNM—7 (Oct. 7, 8, 9, 10, 23); AMNH—26 (July, Aug., Sept.).
Nesting.—Yamashina (1932a:398) records the taking of three nests of the Bridled White-eye at Tinian on January 8, 1932. The nests contained one, two, and three eggs, respectively. The color of the eggs is uniformly pale blue; the nests were situated two to four meters from the ground. Oustalet (1895:207) writes that Marche obtained records of nesting at Saipan in the period from May to July. Of 18 birds taken by Coultas at Tinian in September, 1931, one-half of them had enlarged gonads.
Molt.—Specimens examined that were taken in July, August, September, and October have molting plumage.
Remarks.—Marche obtained the first skins of this white-eye at Saipan; he got 23 specimens in May, June, and July, 1887. The population at Saipan was initially considered similar to that at Guam; it was later given subspecific separation by Dubois. The birds at Tinian exhibit some differences from the birds at Saipan, and it is possible that these two populations should be regarded as subspecifically distinct from one another.
In 1931, Coultas (field notes) found this white-eye common at Saipan and Tinian. He writes "The little fellow has adjusted himself to the gardens and shrubs in the villages. He is a seed eater and makes himself at home now around human habitation. I have seen him climbing over potted plants on the window ledges of dwellings. His cheerful little sibilation uttered continuously while at work or while on the wing makes him friends wherever he goes. He is no longer a bird of the forest as he has none here to go to." Several observers in the late war have published notes on this white-eye. Stott (1947:527) writes that he was reminded of the bush-tit (Psaltriparus) when he observed the behavior of this white-eye; Moran (1946:262) writes that it is "Similar in size and behavior to our vireos." Gleise (1945:220) estimated the population of white-eyes at Tinian at 500 plus in 1945. Downs (1946:104-105) found the birds to be abundant at Tinian; he found them in small flocks in low brush or trees and at edges of open fields as well as elsewhere. He saw a white-eye eating "a large green fuzzy caterpillar."