FAMILY CUCULIDAE 



117 



On the southern slope of the mountains of Chiriqui these birds 

 range regularly to 1,500 meters elevation, less commonly to 2,000 

 meters or a little higher. In the denser, more humid forests that cover 

 the Caribbean side, and in the rain forests of Darien, they are found 

 less often, and only to 600 meters. It is interesting that this species 

 has not been recorded on any of the offshore islands. If it is assumed 



Figure 14. — Squirrel cuckoo, pajaro ardilla, Piaya cay ana thermophila. 



that it is a form that developed in South America, it may not have 

 come north through the Isthmus until the rise in sea level since the 

 close of the Pleistocene isolated Taboga, the Perlas group in the Gulf 

 of Panama, and the islands off the coasts of Veraguas and Chiriqui. 

 In the main, squirrel cuckoos are birds of more open forests, that 

 in denser stands frequent stream borders and other edge. They are 

 found regularly in groves and lines of trees in open fields and savan- 

 nas, occasionally in mangroves and in the inland borders of swamps. 

 When the original tree stand has been cleared second growth is 

 favorable cover. Usually they move quietly among the outer leaves, 



