50 BIRDS OF TASMANIA. 



grey ; under tail coverts white, or very slightly washed with yellow ; 

 irides yellowish-brown; bill black; feet dark brown" (Gould). 

 Dimensions in mm. : Length, 173; bill, 12; wing, 100; tail, 84; 

 tarsus, 25. 



Female. Upper surface olive-brown; under surface pale 

 brown. 



Young. When newly fledged both surfaces are greyish, washed 

 with chestnut; this changes to a plumage closely resembling the 

 adult female's. The young males do not attain full plumage until 

 the second year. 



Nest. Comparatively bulky; constructed of fine twigs 

 and bark, a few leaves being often added; the inside lining 

 usually consists of fine grass and rootlets or fine twigs. A low 

 bush or tree in thick scrub is very frequently chosen as a situation, 

 with the nest placed at the end of a thin bough. 



Eggs. Clutch two to three usually; inclined to oval in shape; 

 texture fine; surface glossy; colour light yellowish- white, darker 

 towards the apex, which is thickly freckled with small spots of 

 umber and dull slate, the latter colour appearing as though beneath 

 the surface ; a few spots of the same colours are scattered over the 

 rest of the surface. Dimensions in mm. of a clutch : (1) 23 x 17, 

 (2) 24 x 17. 



Breeding Season. October to December. 



Geographical Distribution. Tasmania and several of the larger 

 islands in Bass Strait. 



Observations. This sweet-voiced bird is fairly plentiful nearly 

 everywhere in the island where the conditions are suitable for it. 

 It is somewhat shy, however, and is more often heard than seen. 

 Moderately well timbered country is mostly favoured, where it may 

 be seen busily engaged in searching for insects on and under the 

 bark of the eucalypts, also among the foliage ; it is also very adroit 

 at catching its prey on the wing. 



For its size the Grey-tailed Thickhead has a wonderfully deep 

 voice, which is to be heard to the best advantage when the males 

 are challenging one another from the tree-tops at the commence- 

 ment of the breeding season. 



Mr. H. C. Thompson informs me that he has frequently seen 

 birds in immature dress sitting on eggs or tending young, so that 

 he is convinced that, like the Flame-breasted Eobin, this species 

 breeds while yet in adolescent plumage. 



*OLIVE THICKHEAD 

 (Pachycephala olivacea, Vig. and Horsf.) 



Male. Head slate-grey; upper surface, including tail, olive- 

 brown; primaries and secondaries slaty-black, narrowly margined 

 with olive -brown ; throat white, freckled with dark grey ; upper 

 chest grey, rest of under surface light brown; bill black; legs and 



