Acrocephalus arundinaceus orientalis (Temminck and Schlegel): Great Reed Warbler.—Specimens, 6: Tenom: ♀, December 31, 1962, MCT 3546; ♂, January 1, 1963, MCT 3555; ♂, January 2, 1963, MCT 3565; ♀, January 4, 1963, MCT 3575; ♀, January 3, 1963, MCT 3574; ♂, January 4, 1963, MCT 3579.
This species was common in the old paddy near Tenom, which has now grown up to grass and shrubs. I saw one individual also in shrubbery in Jesselton.
Phylloscopus borealis (Blasius): Arctic Leaf Warbler.—I saw this leaf warbler once in dense scrub in the moss forest near Tenom.
Seicercus superciliaris schwaneri (Blyth): White-throated Flycatcher Warbler.—Specimens, 2: 5.5 mi. SW Tenom: ♂ testis 4 × 2 mm., December 23, 1962, MCT 3510; ♀, December 23, 1962, MCT 3511.
In the moss forest this was a common bird that hopped about in the climbing bamboo and scrub.
Orthotomus atrogularis humphreysi Chasen and Kloss: Black-necked Tailorbird.—Specimens, 5: Cocoa Research Station: ♂ testis 4 × 2 mm., 6.5 gm., August 28, 1962, MCT 2827; ♀ oviduct enlarged, brood patch, 5.5 gm., August 28, 1962, MCT 2828; ♂ testis 4 × 2 mm., September 26, 1962, MCT 2967; ♀, November 27, 1962, MCT 3336; ♀, November 28, 1962, MCT 3375.
These birds lived in the secondary forest-edge in dense shrubbery. They were breeding at a time when most other birds seemed to have completed breeding activities; most had begun the post-breeding (prealternate) molt. On October 3, 1962, I saw two adults with two young in nondescript juvenal plumage with virtually no markings and a pale yellow color, unlike that of the adults.
Orthotomus sericeus sericeus Temminck: Red-headed Tailorbird.—Specimens, 1: Cocoa Research Station: ♀ with large ovum, 10.8 gm., August 11, 1962, MCT 2770.
The bird was uncommon at the research station. The one specimen was from the cocoa. I saw two others in secondary growth on the edge of the forest. Possibly this species, like the preceding one, was approaching full breeding activity.
Orthotomus sepium borneonensis Salvadori: Ashy Tailorbird.—Specimens, 8: Cocoa Research Station: ♀ vascular brood patch, oviduct enlarged with one possible collapsed follicle, 7.8 gm., August 22, 1962, MCT 2797; ♀ imm., 8.0 gm., August 28, 1962, MCT 2829; ♂, 8.8 gm., September 10, 1962, MCT 2896; ♂, 8.5 gm., September 10, 1962, MCT 2897; ♂ testis 5 × 3 mm., 8.5 gm., September 11, 1962, MCT 2901; ♀ largest ova 3 mm., 8.5 gm., September 11, 1962, MCT 2902. Tiger Estate: ♀, October 11, 1962, MCT 3000. 5.5 mi. SW Tenom: ♀, December 20, 1962, MCT 3486.