THE BIRDS OF NORTHERN THAILAND 519 



at the base of the inner secondaries wholly or virtually absent. Per- 

 haps the majority of our examples are immature ; they have the gray 

 of the upperparts more or less suffused with rufous and the feathers 

 of the breast and flanks crossed by narrow, wavy bars. 



LANIUS COLLURIOIDES COLLURIOIDES Lesson 



Burmese Chestnut-backed Shrike 



Lanius collurioides Lesson, in Belanger, Voyage aux Indes-Orientales, Zoologie, 



1S34 [=1832], pp. 250-251 (Pegu). 

 Lanius collurioides, Gyldenstolpe, Journ. Nat. Hist. Soc. Siam, 1915, p. 167 



(listed). — de Schauensee, Proc. Acad. Nat. Sci. Philadelphia, 1929, p. 



549 (Chiang Mai, Chiang Rai, Chiang Saen ) .—Riley, U. S. Nat. Mus. Bull. 



172, 1938, p. 478 (Chiang Mai). 

 Lanius hypoleueus siamensis, Gyldenstolpe, Kungl. Svenska Vet.-Akad. Handl., 



1916, p. 40 (Pong Pa O, Khun Tan). 

 Lanius collurioides collurioides, Gyldenstolpe. Ibis, 1920, p. 469 ("Throughout 



Siam"). — Deignan, Journ. Siam Soc. Nat. Hist. Suppl., 1931, p. 145 (Chiang 



Mai) ; 1936, p. 122 (Chiang Mai). — de Schauensee, Proc. Acad. Nat Sci. 



Philadelphia, 1934, p. 221 (Chiang Mai, "Tung Sio", Chiang Saen). 

 Otomela collurioides, de Schauensee, Proc. Acad. Nat. Sci. Philadelphia, 1928, 



p. 562 (Chiang Mai). 



At Chiang Mai the chestnut-backed shrike is quite absent during 

 the period between March 14 (1930, 1931) and May 25 (1935) and de- 

 cidedly rare from the latter date to the beginning of July ; through- 

 out the rest of the year it is one of the commonest lowland birds. Not 

 yet recorded from Nan and Mae Hong Son Provinces, observations 

 and specimens from the remaining districts indicate that its status 

 at a given season is much the same throughout our area. A solitary 

 female collected by me on the Chiang Dao road, 48 km. north of 

 Chiang Mai, March 25, 1936, had the gonads inactive and was evi- 

 dently a sterile individual that had failed to migrate with others of 

 the species. 



This shrike is a more confiding species than Lanius schach tricolor 

 and is constantly seen along the highways, casting itself upon grass- 

 hoppers and other insect prey from hedges, fences, and telegraph 

 wires. It is not known to impale for storage during its stay with us. 



Postj u venal molt is shown by specimens taken between July 10 and 

 September 9; postnuptial molt, by a series collected between July 2 

 and November 26. 



An adult female (January 6) had the irides brown; the bill dull 

 black, fleshy plumbeous at the base of the mandible ; the rictus fleshy 

 plumbeous ; the feet and toes brownish black ; the soles gray ; the claws 

 black. 



The fresh-plumaged adult has the upper half of the head and neck 

 slate, this color paling posteriorly but deepening into black on the 

 forehead, lores, ocular region, and ear coverts (the lores sometimes 



