376 BULLETIN 2 3, UNITED STATES NATIONAL MUSEUM 



to say it, whereas Miss Beecher's lively little friend takes scarcely 

 more than one second. The song is much more like an emphatic 

 sentence made up of words than it is like a phrase of abstract music. 

 The rhythm, of course, is very familiar, actually that of iambic blank 

 verse, rising with force and intention to a climax. Harmonious in- 

 tervals are lacking, but there are complex inflections ending with the 

 characteristic, explosive little slur up and down." Other catch phrases 

 seem to call the song to mind quite vividly, are very^ very glad to meet 

 you (Hoffmann, 1904), or Kalph B. Simpson's (Todd, 1940) dis-dis- 

 dis-dismiss-you, both with a strong accent on the penultimate syllable. 

 This is, of course, the easiest song to recognize, and the only one the 

 amateur is likely to have firmly fixed in his mind. 



Field marks. — The chestnut-sided warbler is one of the easiest of 

 the family to recognize, as both sexes are much alike, the colors of 

 the female being only a little more restricted and duller. The yel- 

 low crown, two yellowish wing bars, chestnut sides, and pure white 

 breast, together with the black and white head pattern, are all con- 

 spicuous field marks for the adults. The young bird in fall plumage 

 lacks the bright yellow crown and most of the chestnut sides, the upper 

 parts being bright greenish yellow and the under parts grayish white, 

 but it has the wing-bars and a white eye ring. 



Enemies. — This warbler is well known to be one of the commonest 

 victims of the cowbird, and Dr. Friedmann (1929) records two cases 

 in which the egg of the imposter had been buried in the bottom of the 

 nest. 



Harold S. Peters (1936) mentions one louse and one mite as external 

 parasites on this species. 



Winter. — The following notes are contributed by Dr. Alexander F. 

 Skutch : "While the black and white warbler spreads in winter over 

 a vast area and appears to be nowhere really common, the chestnut- 

 sided warbler does exactly the reverse, crowds in winter into an area 

 far smaller than its breeding range, and becomes there, during half 

 the year, one of the most abundant of birds. Known in northern Cen- 

 tral America only as a rarely recorded bird of passage, this warbler 

 winters in great numbers in Costa Rica and Panama. In these coun- 

 tries, it appears to be equally well represented in the lowlands of both 

 the Caribbean and Pacific sides, and continues to be abundant upward 

 to an elevation of about 4,000 feet, above which it rapidly decreases 

 in numbers. There appear to be no definite mid-winter records for 

 altitudes above 5,000 feet, although as a transient it is sometimes 

 found considerably higher. 



"In the lofty lowland forests of Costa Rica and Panama the chest- 

 nut-sided warbler is, during the period of its sojourn, the one abun- 

 dant member of the family, whether migratory or resident. It is by 



