Table 50. Measurements of the Subspecies of Zosterops conspicillata
| Subspecies | No. | Wing | Tail | Full culmen | Tarsus |
| Z. c. conspicillata | 43 | 56 | 41 | 13.5 | 19 |
| (52-59) | (37-43) | (13.0-14.5) | (18-20) | ||
| Z. c. saypani | 29 | 52 | 38 | 12.5 | 18 |
| (50-55) | (35-40) | (12.0-13.5) | (17-19) | ||
| Z. c. rotensis | 3 | 53 | 42 | 13.0 | 18 |
| (51-55) | (42-43) | (13.0-13.5) | (18-19) | ||
| Z. c. semperi | 28 | 55 | 38 | 12.5 | 18 |
| (54-57) | (36-41) | (12.0-13.5) | (17-19) | ||
| Z. c. owstoni | 22 | 55 | 36 | 12.5 | 19 |
| (52-57) | (34-38) | (12.0-13.0) | (18-20) | ||
| Z. c. takatsukasai | 16 | 54 | 36 | 13.0 | 19 |
| (53-55) | (34-39) | (13.0-14.0) | (19-20) |
Weights.—The author (1948:73) records the weights of 11 adult males as 9.5-14.0 (10.5), of 3 adult females as 8.0-10.0 (9.3).
Specimens examined.—Total number, 61 (33 males, 17 females, 11 unsexed), as follows: Mariana Islands, USNM—Guam, 27 (May 24, 29, 30, June 2, 3, 25, 28, July 12, 18, 19, 20, 23, 26, Sept., Oct. 8); AMNH—Guam, 34 (Jan., March, July, Aug., Sept., Nov., Dec.).
Nesting.—Seale (1901:58) reports the taking of one nestling and three nests with eggs of the bridled white-eye at Guam in the period from May to July. The NAMRU2 party obtained little evidence of nesting in late May to July. Three males taken in the period of June and July had enlarged gonads. Hartert (1898:57) records several nests taken in February and March at Guam. He writes, "The nest is a fairly deep cup, placed in the fork of a branch, woven together of fine grasses and roots, and on the outside ornamented with cobwebs, wool and cottonwood, varying in width from 8 to 5 cm. The clutches consist of 2 or 3 eggs. The eggs are pale blue, like all Zosterops eggs. They measure 18:13, 17:13.2, 17:12.2, 15.5:12:5, 17:13.5, and between these measurements." Coultas obtained specimens with enlarged gonads in August. According to Oustalet (1895:207), Marche found nests and young in May or June.
Remarks.—Kittlitz obtained the Bridled White-eye at Guam, when he visited the island, in March, 1828. He found the birds common and they reminded him of titmice. Marche obtained a series of 21 skins at Guam in August and September, 1887, and in February and March, 1888. Seale (1901:58) observed the birds in flocks of 10 to 20 in roadside bushes and in waste areas. He mentions that their principal foods are insects. The NAMRU2 party found the birds to be restricted to certain areas on Guam, where they were found in small flocks moving about in low trees. They were taken at only five localities, two of these being at the northern end of the island in vegetation along the high, coastal cliffs. The other localities were in the central part of the island in low trees in the uplands. Strophlet (1946:540) found them in grasslands on the foothills. Arvey (field notes) saw a flock of 12 white-eyes at Mount Tenjo in July, 1946.
The white-eye is a very active bird, always moving rapidly through the vegetation or flying across open areas to disappear into scrub foliage. As they move about they make a twittering sound, which is considered to be a flocking call.
Zosterops conspicillata saypani Dubois
Bridled White-eye
Zosterops conspicillata Saypani Dubois, Syn. Avium, 1, 1902, p. 711. (Type locality, Saypan.)