This species was common in the moss forest near Tenom. The female specimen with collapsed follicles indicates that some of the birds were in breeding condition. All specimens were netted.
Trichastoma malaccense poliogenys (Strickland): Short-tailed Jungle Babbler.—Specimens, 17: Cocoa Research Station: ♂ testis 7 × 4 mm., 24.5 gm., July 31, 1962, MCT 2687; ♀, September 5, 1962, MCT 2874; ♀, September 24, 1962, MCT 2941; ♂, November 29, 1962, MCT 3387; ♀, November 29, 1962, MCT 3388; ♂, December 1, 1962, MCT 3400; ♀, November 12, 1962, MCT 3262. Kalabakan: ♂, November 16, 1962, MCT 3292. Cocoa Research Station: ♂, June 11, 1963, ADG 123; ♂, June 12, 1963, ADG 127; ♀, June 13, 1963, ADG 132. Ulu Balung Cocoa Estate: ♂, July 9, 1963, ADG 179; ♂, July 9, 1963, ADG 179 (sic). Oil Palm Research Station: ♂, August 10, 1963, ADG 219; ♂, August 12, 1963, ADG 225; ♀, August 13, 1963, ADG 236; ♀, August 23, 1963, ADG 255.
This terrestrial species was common in primary forest, and occasionally in secondary forest, in low trees or around brush piles. On September 24, by "squeaking," I so aroused one bird that it ran back and forth on a limb of a fallen tree in great agitation. The specimen taken on November 12 was in heavy molt; it lacked tail feathers and the primaries were being replaced.
Trichastoma bicolor (Lesson): Ferruginous Jungle Babbler.—Specimens, 6: 12 mi. N Kalabakan: ♂, October 24, 1962, MCT 3143; ♀, October 26, 1962, MCT 3161; ♂, November 10, 1962, MCT 3135; ♀, November 12, 1962, MCT 3255. Oil Palm Research Station: ♂, August 12, 1963, ADG 266; ♀, August 28, 1963, ADG 269.
All specimens were taken in primary forest.
Trichastoma sepiarium harteri (Chasen and Kloss): Horsfield Jungle Babbler.—Specimens, 6: Cocoa Research Station: ♂ testis 8 × 5 mm., 25.7 gm., July 24, 1962, MCT 2652; ♂ testis 8 × 5 mm., 28.2 gm., July 27, 1962, MCT 2668; ♂ testis 8 × 7 mm., 28.2 gm., July 31, 1962, MCT 2688; ♂, June 15, 1963, ADG 142. 12 mi. N Kalabakan: ♂ testis 8 × 5 mm., November 8, 1962, MCT 3233. Oil Palm Research Station: ♀, September 5, 1963, ADG 275.
This babbler tends to inhabit secondary growth more than does T. malaccense and was partly arboreal, occasionally ranging as high as 20 feet above ground. It occurred occasionally in flocks of four or five.
Malacopteron magnum magnum Eyton: Greater Red-headed Babbler.—Specimens, 12: Cocoa Research Station: ♂ testis 7 × 5 mm., September 7, 1962, MCT 2886; ♂ testis 9 × 5 mm., October 4, 1962, MCT 2990; ♂, November 30, 1962, MCT 3437; ♀, November 27, 1962, MCT 3340; ♀, April 30, 1963, ADG 91; ♂, June 14, 1963, ADG 136; ♂, July 9, 1963, ADG 178. Ulu Balung Cocoa Estate: ♂, July 11, 1963, ADG 191; ♂, July 16, 1963, ADG 205. 12 mi. N Kalabakan: ♂, October 22, 1962, MCT 3124; ♀, October 28, 1962, MCT 3176; ♂, October 28, 1962, MCT 3177.
This babbler was common at the Cocoa Research Station but uncommon elsewhere. It seemed to prefer primary forest and was only rarely seen in the cocoa. My series shows that this species was common at Quoin Hill and M. cinereum was rare, while the opposite obtained 12 miles north of Kalabakan. For the moment this cannot be explained. Possibly these two species are competitive and tend toward mutual exclusion. Since the birds were mostly netted, it is assumed that I obtained a random sample. My observations at Quoin Hill seem to bear out the specimen record.
The specimens in my series of M. m. magnum are more nearly black on the crown than those labelled M. m. saba in the U. S. National Museum (from the Segah River), but there was much variation in the amount of black on the crown in all series examined. I consider M. m. saba to be synonymous with M. m. magnum.
Malacopteron cinereum cinereum Eyton: Lesser Red-headed Babbler.—Specimens, 29: Cocoa Research Station: ♂, December 2, 1962, MCT 3428; ♀, June 11, 1963, ADG 124; ♂, July 9, 1963, ADG 178. 12 mi. N Kalabakan: ♂, October 13, 1962, MCT 3025; ♀, October 13, 1962, MCT 3030; ♂, October 13, 1962, MCT 3032; ♀, October 14, 1962, MCT 3042; ♂, October 14, 1962, MCT 3043; ♀, October 16, 1962, MCT 3059; ♂, October 21, 1962, MCT 3119; ♂, October 22, 1962, MCT 3128; ♀, October 24, 1962, MCT 3136; ♂, October 28, 1962, MCT 3178; sex?, October 31, 1962, MCT 3188; ♀, November 7, 1962, MCT 3219; ♀, November 7, 1962, MCT 3220; ♂, November 12, 1962, MCT 3263; ♀, November 12, 1962, MCT 3264. Kalabakan: ♂, November 15, 1962, MCT 3282; ♂, November 15, 1962, MCT 3284; ♀, November 15, 1962, MCT 3285. Ulu Balung Cocoa Estate: ♂, July 13, 1963, ADG 197. Oil Palm Research Station: sex?, August 16, 1963, ADG 245; ♀, August 28, 1963, ADG 272. Pintasan Agriculture Station: ♂, October 17, 1963, ADG 318; ♂, October 18, 1963, ADG 319; ♂, October 18, 1963, ADG 320; ♀, October 18, 1963, ADG 321; ♀, October 18, 1963, ADG 322. See remarks under M. magnum.