554 BIRDS OF THE REPUBLIC OF PANAMA PART 3 



While the range as a whole coincides with that of the Yellow- 

 bellied Elaenia, the present species usually is less in evidence, as it 

 remains more in cover and is much less vociferous in its calls. On 

 the whole, in its actions it is more like the Mountain Elainea. It 

 differs from that species in plainer coloration, and its slightly smaller 

 size. Lesser Elaenias come constantly to fruiting trees and shrubs 

 to eat the berries, a conspicuous habit, but one that supplies only a 

 part of their diet. Constantly they search through leaves and smaller 

 branches for insects and spiders whose fragments often completely 

 fill their stomachs. Some of this food may be taken in short snatches 

 and little flycatching sallies. It is usual also to find their stomachs 

 filled with small fragments of chitin from bees, other small hymen- 

 optera, and a variety of beetles, most captured in the air, but so 

 quietly that the considerable proportion of insects in the food may 

 not be suspected. 



Skutch in a detailed account of life history and habits in this species 

 (Pac. Coast Avif. no. 34, 1960, pp. 307-318), mainly as seen in Costa 

 Rica where they are common, described the usual note as "a low 

 short whistle, sometimes soft and sometimes harsh in tone, which is 

 often repeated over and over at intervals of a few seconds." They 

 also have a dawn song of several syllables. In evening, from March 

 through June, birds assumed to be males regularly rise in twisting 

 flight in the air, and then suddenly drop back to cover as they give this 

 song. 



The nest, built by the female, is an open cup placed in a fork in 

 a bush or tree from half a meter to 10 meters from the ground. It is 

 built of bits of dry grass, moss, and other fibrous material, bound as 

 needed by cobweb. In general the nest resembles that of the Yellow- 

 bellied Elaenia, but may be more lightly formed and more flimsy in 

 construction, also with fewer feathers for lining. The outer surface 

 varies in ornamentation from a slight to a heavy covering of moss. 

 Two eggs are usual in a set, though nests often hold only one. They 

 are "short ovate and blunt, dull white, with a wreath about the thicker 

 end of usually fine but sometimes heavy spots of brown," varying in 

 depth of shade. In some, spots of this color are scattered over the 

 entire surface and may vary in shade to lilac. Eggs range in size 

 from 19.8 X 14.3 and 19.4 x 15.5 to 16.7 X 13.9 mm. 



Incubation is by the female alone, with the male assisting later in 

 feeding the young. These on hatching have pink skins with tufts of 

 long, light gray down in tracts along the center of the crown, above 

 the eye, and on the hindhead, back, and sides. Shorter bits that in part 



