SMOOTH-BILLED ANT 21 



always loholly denuded. * * * So cleanly and evenly is it done, 

 and to such an extent, that I feel confident it is the ^York of the 

 birds themselves, their beaks alone being able to accomplish it. At 

 the same time it is easy to see that the marks and scratches at the 

 sides are the result of friction with the twigs and leaves of the nest." 



The measurements of 63 eggs average 35.03 by 26.27 millimeters; 

 the eggs showing the four extremes measure 40.4 by 28, 36.5 hy 30, 

 and 29^21 by 23.37 millimeters. 



Young. — Alexander F. Skutch has sent me the following notes 

 on the development of young smooth-billed anis, as observed by him 

 on Barro Colorado Island, Panama: "The newly hatched ani is 

 covered with black skin quite devoid of any trace of feathers. Its 

 eyes are tightly closed. The development of this naked, helpless, 

 little creature is amazingly rapid. By the second day the sheaths 

 of the flight plumes have already begun to sprout. By the third 

 day the eyes are open, and the sheaths of the contour feathers have 

 begun to push out from the skin. The pinfeathers grow rapidly 

 and become verj^ long before they begin to release the true feathers 

 which they enclose. When the young ani is 5 days old, the body 

 feathers peep from the ends of their sheaths. At this age, the 

 nestling could hang by one foot from my finger, and pull itself up 

 by the use of its feet and bill, which was hooked over the sup- 

 port. When placed on the ground, it attempted to crawl away 

 through the grass, and might have succeeded in escaping if I had not 

 watched it carefully. Returned to the nest, it would not remain in 

 the bowl, but climbed out to perch on the rim, where it uttered a 

 little whine. 



"When I approached the nest on the following day, the 6-day-old 

 youngster hopped out and began to climb through the thorny 

 branches of the orange tree, but soon it lost its hold and fell to the 

 ground. Wlien I picked it up, it uttered a weak imitation of the 

 parents' usual call. The flight feathers, as well as the body feath- 

 ers, were now pushing forth from their sheaths, and the latter were 

 longer than on the preceding day. Much bare skin was, however, 

 still visible between them. On the following morning the nest was 

 empty ; and I could not discover what had befallen the occupant." 



Plumages. — The youngest bird I have seen is about half grown and 

 fully feathered. The contour plumage is soft and short, "bone 

 brown" on the under parts and somewhat darker above ; the wings and 

 tail are glossy, purplish black, much like those of the adult; the bill is 

 smaller and less specialized than that of the adult. On account of the 

 extended breeding season, it is difficult to give any definite dates for 

 the molts. I have seen a young male, taken March 7, that was just 

 completing the molt of the wings and tail, but the body plumage was 



