2^8 Cherrie on Two Costa Rican Birds. ,"j 



NOTES ON TWO COSTA RICAN BIRDS. 



BY GEORGE K. CHERRIE. 



Ramphoccelus costaricensis. 



I recently published some notes on this species, 1 which I may 

 be pardoned for repeating in this place with a few additions, as 

 the original description of the species was published in 'The Auk' 

 (Vol. VIII, 1891, p. 62). At that time I believed the male and 

 female to be alike in plumage, the six specimens I then had 

 — three males and three females — being exactly alike. However, 

 during a recent exploring trip along the southwest coast region 

 of Costa Rica, I was fortunate in securing a large series of speci- 

 mens of this bird of both sexes and all ages. This species clearly 

 demonstrates that the adult male costaricensis is distinguishable 

 from the adult male passerinii only by its slightly larger size 

 and the different wing formula. Females and young males are 

 at a glance distinguishable from female and young passeri?iii by 

 the bright ochraceous rufous breast and rump. 



During my stay at Boruca and Palmar (the last of February) 

 the breeding season was at its height, and I observed many of the 

 Costa Rica Red-rumps nesting. In almost every instance 

 where possible I collected both parents of the nests, and in the 

 majority of cases found the males wearing the same dress as the 

 females! In a few instances the male was in mottled plumage, 

 evidently just assuming the adult phase, and in a lesser number 

 of examples the male was in fully adult plumage — velvety black 

 and crimson red. 



From the above it is clear that the males begin to breed 

 before they attain fully adult plumage, and that they retain the 

 dress of the female until, at least, the beginning of the second 

 year. 



While on this trip I had many proofs that — in spite of its rich 

 plumage, and being a bird of the tropics — R. costaricensis is 

 well worthy to hold a place of honor among the song birds. 

 And if the bird chooses an early hour and a secluded spot for 



1 Anales del Instituto Fisico-geografico y del Museo Nacional de Costa Rica, III, 

 1890, p. 135. 



