48 TJ.S. NATIONAL MUSEUM BULLETIN 2 37 paet i 



migratory lines converge southwardly until the width of the lane narrows down 

 to about 700 miles, where the grosbeaks leave the United States between eastern 

 Texas and Appalachicola Bay, Florida. Instead, however, of continuing to con- 

 verge, the eastern and western limits of the migratory lane remain nearly parallel, 

 so that the birds enter the northern part of their winter range in southern Mexico 

 through a gate of about the same width. Further south, the tapering shape of 

 Central America results in a greater concentration, reaching its extreme in the 

 Isthmus of Panama. Rose-breasts that travel as far as South America spread 

 out through Colombia, Venezuela and Ecuador. 



Winter. — Alexander F. Skutch contributes the following: "With 

 rare exceptions, the rose-breasted grosbeaks do not reach Central 

 America until the middle of October. Carriker (1910) records 

 a young male taken at Escazu in the Costa Rican highlands at 

 the surprisingly early date of August 13, 1902, but my own earliest 

 date of arrival is October 16, 1942, the locality being the basin of El 

 General in southern Costa Rica. Soon the grosbeaks spread thinly 

 over the entire region, settling down to spend the winter from Guate- 

 mala to Panama, and from the lowlands of both coasts up to no less 

 than 8,500 feet in the highlands, where they brave the heavy nocturnal 

 frosts of the winter months. Although common as winter residents 

 in only a few localities, they are more abundant in the highlands from 

 3,000 feet upward than in the warm lowlands, and in Guatemala 

 than farther to the south in Costa Rica. Likewise they are more 

 gregarious in the highlands, where I once counted 20 in a flock, than 

 at lower altitudes, where it is exceptional to meet more than 3 or 4 

 together. They frequent clearings and plantations with scattered 

 trees and light or open woodland; but I have not met them in heavy 

 lowland forest. They appear to avoid excessively wet districts such 

 as the northern slopes of the Cordillera Central of Costa Rica. 



"On the Hacienda 'Chichavac' at an altitude of about 8,500 feet 

 in the mountains above Tecpan in the Department of Chimaltenango 

 in west-central Guatemala, rose-breasted grosbeaks often visited the 

 vegetable garden beside the house, and its vicinity. Here I 

 first met them in November 1930, and they were present when I 

 returned at the beginning of 1933, when about 20 were counted. 

 By March some of the males had put on theu- full nuptial attu'e, and 

 were resplendent in white, black, and rose. The last of the flock departed 

 on April 6. They remained absent for Gji months, returning on 

 October 19, when I found three in the hedgerow at the far end of the 

 garden, almost in the same spot where I had seen the last of the 

 flock the preceding spring. Two were females modestly clad in buffy- 

 brown and grayish-white; their companion was a male attired almost 

 as plainly as they, but there was a tinge of rose on his white breast 

 to remind me of the warm rosy shield that had covered it when 

 he left in the spring, and his wings were conspicuously marked with 



