76 BULLETIN 186, UNITED STATES NATIONAL MUSEUM 



The vultures are inactive on dark days and in the morning before the 

 warmth of the sun is felt, but at other times they are rarely out of 

 sight somewhere in the sky. At Chiang Mai the present species 

 roosted in some numbers in trees on the lower slopes of Suthep and, 

 in addition, had certain favorite tall trees in the city, where numbers 

 slept together. 



The whiteback often breeds in the neighborhood of villages, if there 

 are trees sufficiently large. Gyldenstolpe reported seeing several nests 

 near Chiang Mai. I saw a bird on a nest along the Chiang Mai-Ko 

 Klang road, March 8, 1937, and another brooding near Chiang Rai, 

 May 5, 1936. 



A male from Chiang Mai had the irides yellowish brown ; the eyelids 

 plumbeous-blue ; the skin of the head dusky gray ; the neck plumbeous, 

 mottled with dusky gray; the bill slaty, with the base of the culmen 

 olive-plumbeous; the cere black; the feet and toes black, the scutes 

 edged with gray ; the claws black. 



The adult has the upperparts brown, with lower back and rump 

 white ; the primaries and tail blackish ; a white ruff around the neck, 

 not connected across the chest ; the underparts light brown, with flanks 

 white. The immature has the upperparts dark brown ; the underparts 

 dark brown with light brown shaft streaks ; the ruff, flanks, and lower 

 back white, as in the adult ; the under wing coverts pure white, form- 

 ing a large area conspicuous in flight ; the head and neck covered with 

 white down. 



CIRCUS MELANOLEUCOS (Pennant) 



Pied Harrier 



Falco melanoleucos Pennant, Indian zoology, 1769, p. 2, pi. 2 (Ceylon). 



Circus melanoleucus, Gyldenstolpe, Journ. Nat. Hist. Soc. Siam, 1915, p. 234 

 (listed) ; Kungl. Svenska Vet.-Akad. Handl., 1916, p. 123 (Khun Tan, Mae 

 Tha river, Nong Bia) ; Ibis, 1920, p. 748 ("Northern Siam"). — de Schauen- 

 see, Proc. Acad. Nat. Sci. Philadelphia, 1929, p. 579 (Chiang Mai, Chiang 

 Saen, 30 km. north of Chiang Rai). — Deignan, Journ. Siam Soc. Nat. Hist. 

 Suppl., 1931, p. 166 (Chiang Mai) ; 1936, p. 77 (Chiang Mai). 



The pied harrier is a common and widely distributed winter visitor 

 from October 4 (Chiang Mai) to April 15 (Chiang Dao). The latter 

 date is based upon a specimen in Stockholm taken by Dr. P. Fejos. I 

 have collected it at Chiang Mai, Chom Thong, Mae Sariang, and Ban 

 Mae Chai Tai and have observed it at numerous other lowland locali- 

 ties. 



Of the three harriers now known from northern Thailand, only the 

 present species occurs in great numbers. It is to be seen flying low 

 over the ricefields and marshes, a graceful, long-winged, long-tailed 

 hawk, which systematically quarters the ground and occasionally 

 hovers at one spot, then dives to the kill. De Schauensee has recorded 

 that one of his specimens had a lizard in its stomach; stomachs I 



