BIRDS OF NORTH AND MIDDLE AMERICA 405 



Mus. Comp. Zool.). — Swann, Synop. Accip., ed. 2, 1922, 97 (St. Vincent; 

 Santa Lucia; Trinidad); Monogr. Birds Prey, i, 1930, 458 (monogr.). 

 Buteogallus anthracinus cancrivorus Peters, Check-list Birds of World, i, 1931, 

 245. — Belcher and Smooker, Ibis, 1934, 591 (Trinidad; uncommon res.; 

 eggs). — Roberts, Trop. Agr., xi, No. 4, 1934, 5 (Trinidad). — Bond, Birds 

 West Indies, 1936, 68, 69, in text (West Indies; descr. ; distr. ; egg meas.), 

 414; Check List Birds West Indies, 1940, 24 (West Indies; distr.; St. Vincent, 

 common; St. Lucia and Grenada, accidental; no spec; Trinidad), ed. 2, 1945, 

 24.— Aldrich, Sci. Publ. Cleveland Mus. Nat. Hist., vii, 1937, 47, 48 (meas.; 

 distr.). — Danforth, Journ. Agr. Univ. Puerto Rico, xxiii, 1939, 21 (Guade- 

 loupe; hypothetical). — Street, Auk, Ixiii, 1946, 371 (Trinidad). 



BUTEOGALLUS ANTHRACINUS SUBTIUS (Thayer and Bangs) 



Pacific Crab Hawk 



Adult (sexes alike). — Similar to that of Buteogallus anthracinus 

 anthracinus, but smaller and with a few more whitish feathers, on the 

 average, in the malar region.^ 



Juvenal (sexes alike). — Similar to that of Buteogallus anthracinus 

 anthracinus, but averaging less heavily streaked below with fuscous, 

 the thighs averaging less thickly barred, and the upper wing coverts 

 and the secondaries averaging more edged or spotted with rufescent.' 



Natal down. — Not known. 



Adult maZe.— Wings 328-350 (336); tail 178-200 (186.8); culmen 

 from the cere 25-27 (25.5); tarsus 80-87.5 (82.4); middle toe without 

 claw 42.5-45 (43.4 mm.).* 



Adult female.— Wing 345-352; tail 186-202; culmen from cere 

 26.5-27; tarsus 82-83; middle toe without claw 45 mm.^ 



Range. — Mangrove swamps of the Pacific slope from Chiapas, 

 Mexico, and El Salvador (Puerto del Triunfo, Barra de Santiago, La 

 Libertad, Acajutla) to Darien, Panama, to Gorgona Island, Colombia, 

 and to southern Ecuador (Pund Island and Lechugal). 



2 In the original description of this form (Bull. Mus. Comp. Zool., xlvi, No. 5, 

 June 1905, 94), it is stated that the "white central tail band and terminal margin 

 narrower . . . [than in typical anthracina] and with the ground color of 

 the broad mottled band extending across the secondaries, bright cinnamon rufous, 

 this band in true . . . anthracina having the ground color dull grayish only 

 tinged with rufous on the inner edges of some of the feathers." Only one adult 

 bird was seen by the describers; a series of 6 adults examined in the writing of this 

 book fails to bear out any constant difference in these features from the nominate 

 form. 



3 Chapman (Bull. Amer. Mus. Nat. Hist., Iv, 1926, 233-234) has described 

 a plumage I am unable to place (bird not seen by me). It is said to be an imma- 

 ture bird from Puna Island, Ecuador. The "prevailing color is brownish, darker 

 below, with a fuscous tail and broken white sub-terminal band; the upperparts 

 are mottled or barred with rusty and the inner web of the inner wing quills is 

 largely this color." 



^ Five specimens: 1 (type) from Gorgona Island, Colombia; 4 from El Salvador, 

 * Two specimens from El Salvador. 



