FAMILY CUCULIDAE 131 



to the lower Rio Bayano beyond Chepo. In February 1956, they were 

 common at San Felix and Las Lajas in eastern Chiriqui, and from 

 January to March 1958, in Bocas del Toro, from the lower Rio 

 Sixaola through the area around Changuinola and Almirante, with 

 records from Isla Colon, Isla Pastores, Roldan and Coco cays, and 

 the fields near the mouth of Rio Occidente and on Quebrada Garay. 

 The only offshore islands on which I have seen them are Isla Gober- 

 nadora and Isla Cebaco. On Cebaco I found a small flock on March 

 26, 1962, in old cornfields on the western end back of the bay called 

 Caleta Caiman. Three years later I saw them near Platanal at the 

 other end of the island. 



Elsewhere in Central America the groove-billed ani ranges in moun- 

 tain areas through open country to elevations of 1,800 to 2,200 meters, 

 but in Panama at present it is known only in the lowlands. 



Groups of these anis are territorial in that they remain in one 

 general area, but intruders of their own kind are not molested. The 

 smooth-billed ani, however, sometimes will not tolerate these smaller 

 birds. In the drier regions, in which groove-billed anis are common, 

 they range in open areas or in scattered bush. While this seems a 

 normal habitat, they also come into sections of heavier precipitation 

 where there is sufficient open range, usually in pastures but also in 

 grass-grown marshes. They also frequent marshes in the savannas 

 during the rainy season. Like the related species, they feed constantly 

 around livestock for the insects flushed by the grazing animals. My 

 first sight of them along the Rio Chagres at Juan Mina was of a 

 little flock that accompanied three horses grazing in a small marsh. 



At casual glance the groove-bill may not be distinguished from the 

 smooth-billed species as the two are alike in form, color, and manner- 

 isms. The easily seen bill markings serve to separate them readily on 

 close examination. Call notes also are quite different, the groove-bill 

 usually being less voluble. Its calls are higher pitched, often squeaky, 

 and of a more chattering sound. 



Their food is mainly insects, with orthoptera a prominent item. 

 Small lizards are captured, though sometimes swallowed with dif- 

 ficulty. Berries also are eaten. 



Birds at rest constantly perch side by side touching one another, 

 often three together. They preen the heads and necks of those beside 

 them, and, as stated above, never appear quarrelsome. At Las Lajas, 

 eastern Chiriqui, on February 24, 1956, I found a nest in a low thicket 

 that stood in water in a shallow lagoon. The birds had built in a 

 spreading fork in a thick-leaved bush a meter above the water. The 



