FAMILY ARDEIDAE 93 



tail 78.4-82.8 (80.6), culmen from base 87.0-98.4 (93.7), tarsus 

 85.5-99.0 (90.8) mm. 



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

 Fairly common in lowland areas, along the lower courses of rivers, 

 and in marshes ; seen at the highland lakes near El Volcan, Chiriqui ; 

 one specimen in the British Museum (Natural History) taken on Isla 

 del Rey June 26, 1924, by naturalists on the St. George Expedition; 

 one seen on Isleta Malaga, January 29, 1960. 



There is record of one banded in South Carolina and taken sub- 

 sequently on the lower Rio Tuira. 



In the main these slender herons are solitary, feeding somewhat 

 apart from other species. They are patient fishermen, that stand 

 quietly, or walk stealthily in search of prey, though occasionally I 

 have seen one seize a minnow with a quick dart of the long bill, when 

 the bird was flying low over shallow water. 



Though no breeding colonies are on record as yet, it appears cer- 

 tain that they nest in Panama. Festa collected one on the Rio Sabana, 

 Darien, in July 1895. An adult male in full breeding plumage in the 

 collection of the Gorgas Memorial Laboratory was taken on the canal 

 at Boca del Drago, Bocas del Toro, on June 3, 1962. On December 

 17, 1955, at Juan Mina, Canal Zone, I watched an immature bird, 

 barely grown, fishing about the dock. This bird was completely fear- 

 less as it was often within 10 meters of me, in contrast to the wariness 

 of older individuals. It is probable that northern winter migrants come 

 to the Caribbean coast, for in 1958 during the first week in February 

 there was a sudden decrease in their number around Almirante Bay, 

 an indication that part of those observed earlier had begun their return 

 northward. 



BUBULCUS IBIS IBIS (Linnaeus): Cattle Egret; Garcilla Bueyera 

 Ardea Ibis Linnaeus, Syst. Nat., ed. 10, vol. 1, 1758, p. 144. (Egypt.) 



Smallest of the white herons found in Panama, marked from the 

 other small species by the yellow (in breeding season reddish) bill. 



Description. — Length 460 to 560 mm. Plumage white, with buff 

 on the crown, more extensive during the breeding season, and found 

 then also on the back and the breast. 



Iris yellow ; bill yellow ; legs dull greenish. In nesting season the 

 bill becomes reddish at the base, and the tarsi also are dull reddish. 



Measurements of two taken at La Jagua are as follows: Male, 

 wing 238, tail 86, culmen from base 60.7, tarsus 79.2 mm. 



Female, wing 227, tail 83, culmen from base 54.7, tarsus 72.6 mm. 



