FAMILY THRAUPIDAE 



391 



nest itself is a shallow cup with an outer layer of vines, creepers, moss, 

 and soft bark; the inner layer is made of tiny palm fibers. In Vene- 

 zuela, the usual clutch is three eggs, which are porcelain white in color 

 and average 21.5x15.0 mm. Incubation is performed by the female 

 and takes approximately 15 days. The young are hatched with a sparse 

 coating of yellowish-pink down the same color as their skin. They are 

 fed insects and small amounts of fruit by both parents, although the 

 female brings in far more than her mate; males usually do not begin 

 feeding until the young are so large that the female alone could not 

 satisfy them. The young leave the nest cavity at 24 days of age. At 

 this time they still have short tails and sparsely- feathered heads, but 

 can fly 40 or 50 m without previous practice. They are attended by the 

 female for 8 to 10 days, while the males remain on their territory. Soon 

 the adults join the flocks formed by juveniles and, at least at the site 

 where Schaefer studied them in Venezuela, depart for lower elevations. 



The Swallow-Tanager is often placed in a separate family, largely 

 on account of its broad, flat bill, long wings, short legs, and nesting 

 habits. Sibley (Bull. Brit. Orn. Club, 1973, pp. 75-79), however, sug- 

 gests that its specialized anatomical characters are only feeding adapta- 

 tions. He concluded that Tersina is a tanager and is most closely re- 

 lated to the genera Thraupis and Tangara. Raikow (Bull. Carnegie 

 Mus. Nat. Hist. no. 7, 1978, p. 31 ) similarly concludes, on the basis of 

 its appendicular myology, that Tersina is a tanager, but he considers it 

 an "aberrant" thraupid "whose intergeneric affinities are obscure" 

 (op. cit., p. 41 ). 



CHLOROPHONIA OCCIPITALIS CALLOPHRYS (Cabanis): Blue- 

 crowned Chlorophonia, Tanagra Cejidorada 



Triglyphidia callophrys Cabanis, 1860, Journ. f. Ornith., 8, p. 331. (Costa Rica.) 



Small; bright green with blue central crown, male with yellow un- 

 dersurface. 



Description. — Length 118-137 mm. Adult male, forehead light 

 green; forecrown and stripe to nape dark yellow; central crown to nape 

 light blue-violet; very thin band across nape to side of breast light blue; 

 lores and narrow orbital ring light blue; sides of face, to edge of blue 

 nape band, throat and upper breast, bright green, edged with fine black 

 stripe on sides of breast; rest of upper surface and wing coverts bright 

 shiny green; remiges black, narrowly edged green on outer web of 

 primaries; outer web of secondaries almost entirely green; tertials 

 green; central pair of rectices entirely green, others black on inner web, 



