FAMILY ARDEIDAE 99 



nest is built in low trees, and that the bird lays two eggs, but gives 

 no other details. 



While this species appears related to the black-crowned night 

 herons, which it resembles in the form of the nuchal plumes, it differs 

 definitely in lack of a well defined immature plumage. 



NYCTICORAX NYCTICORAX HOACTLI (Gmelin): Black-crowned Night 

 Heron; Zorro de Agua 



Ardca Hoacfli Gmelin, Syst. Nat., vol. 1, pt. 2, 1789, p. 630. (Valley of Mexico.) 



Adult, crown and back greenish black, white below. Bill more 

 slender than in the yellow-crowned night heron. 



Description. — Length 560 to 660 mm. Adult, back and crown 

 glossy greenish black, except forehead and line above eye which are 

 white ; wings and tail gray ; neck pale gray ; below white ; two slender, 

 white nuchal plumes, that reach a length of more than 200 mm, in 

 breeding season. 



Immature, above grayish brown, streaked heavily with white ; be- 

 low white, streaked heavily with grayish brown, except on the throat 

 and abdomen. Second-year birds are plain gray above, unstreaked. 



Measurements. — Males (5 from United States, Panama, Colombia, 

 and Venezuela), wing 290-307 (298), tail 110.0-117.6 (114.3), 

 culmen from base 70.8-74.3 (72.5), tarsus 71.8-86.5 (78.9) mm. 



Females (5 from United States and Colombia), wing 290-298 

 (293), tail 108.2-114.5 (110.9), culmen from base 70.3-74.6 (73.7), 

 tarsus 74.8-84.8 (81.7) mm. 



Resident, and in part a winter visitor from the north. Fairly com- 

 mon in the coastal lowlands. 



This night heron was found by Maj. Gen. G. Ralph Meyer on 

 Farallon Rock, off Isla Taboguilla, where there were large young on 

 April 9, 1944 ; and on Isla Changame March 16, 1941. I recorded it in 

 the Perlas group on Isla San Jose, February 21, 1944, and at Isleta 

 Malaga, January 29, 1960. About 30 were seen in the low brush on 

 the summit of Isla Villa, off the coast of Los Santos, February 28, 

 1957. One in the British Museum was taken on Isla Taboga on Sep- 

 tember 24, 1924. 



There is record of one banded in Michigan, June 26, 1941, that was 

 shot near Rio Hato in June 1949. 



These herons in the main are nocturnal and during the day remain 

 in dense tree tops in wooded swamps, tall mangroves, or along the 

 lower courses of rivers, and so it is only casually that one is seen as 

 it takes flight heavily when alarmed by human intrusion. From sun- 



