THE BIRDS OF NORTHERN THAILAND 159 



Hierococcyx sparverioid.es sparverioides, Chasen and Boden Kloss, Journ. Siam 

 Soc. Nat. Hist. Suppl., 1932, p. 234 (Doi Suthep).— Deignan, Journ. Siam Soc. 

 Nat. Hist. Suppl., 1936, p. 87 (Doi Sutbep).— de Schauensee, Proc. Acad. 

 Nat. Sci. Philadelphia, 1934, p. 257 (Doi Suthep). 



The large hawk cuckoo is a common resident of the hills throughout 

 our provinces ; it is a bird of the more open forest, whether this be light 

 evergreen, mixed-deciduous, or pine. In the neighborhood of Chiang 

 Mai it is normally found only on Doi Suthep from 2,700 to 5,500 feet, 

 but I have taken three wandering immature examples on the plain: 

 one, December 14, 1935, and two, November 25, 193G. Young birds 

 seem frequently to come into lowland districts; I collected one at 

 Muang Fang, July 6, 1936, and another at Wiang Pa Pao, July 26, 

 1935. Eisenhofer sent to Stockholm three specimens, including a 

 juvenile, from Khun Tan. 



While any one of a number of our cuckoos might with reason be 

 called a brain-fever bird, the name is properly applied to the present 

 species, whose call is a shrill brain-fever, repeated again and again, 

 each reiteration higher and louder than the preceding, until the bird 

 can do no more and begins all over again. This is a characteristic 

 sound of our mountain forests during the breeding season; on Doi 

 Suthep it was heard on all sides, day and night, from February 6 

 (1937) to June 14 (1930). Despite the obvious commonness of the 

 species, it is rarely observed, for it keeps to the tops of densely 

 foliaged trees, where it remains motionless for long periods, and when 

 not in song it will virtually never be seen. 



I have taken juveniles on April 29 (Doi Ang Ka) and July 26 

 (Wiang Pa Pao). A bird of July 6 (Muang Fang) is molting from 

 juvenal dress to what seems to be a subadult plumage; the latter is 

 shown in a specimen of December 14 (Chiang Mai). 



The very young example of April 29, a female, had the irides dull 

 gray-brown; the edges of the eyelids yellow; the maxilla brownish 

 black, with the culmen tinged olive at the base and the edges of the 

 commissure dark brown on the apical half, yellow on the basal half ; 

 the mandible black at the extreme tip, then dull yellow, next olive, and 

 near the base on either side slaty blue; the rictus and interior of the 

 mouth bright yellow ; the feet and toes bright yellow ; the claws horny 

 yellow. 



This species, at any age, bears an extraordinary resemblance to an 

 accipitrine hawk, both in shape and coloration. The adult has the 

 crown and nape gray, this color changing gradually to brownish gray 

 on the remaining upperparts and tail ; the tail crossed by several broad 

 blackish bands; the throat gray, mottled with white and rufous; the 

 breast similar but with rufous the prevailing color; the remaining 

 underparts closely barred with white and blackish brown and suffused 

 with rufous; the under tail coverts white, more or less barred with 



