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BIRDS OF THE REPUBLIC OF PANAMA PART 4 



Eisenmann and E. S. Morton in October 1965 and Ridgely in early 

 April 1976 found them also within tall forest areas of Coiba, but only 

 in lower growth. The notes heard were essentially as on the mainland. 



Family PARULIDAE: Wood Warblers, Reinitas 



Forty-eight species of wood warblers have been found in Panama. 

 This total includes 34 North American migrants, mostly from the east- 

 ern half of the continent, that winter in Panama or pass through on 

 their way north or south. Some are extremely common, especially in 

 the periods from September to early November and again in March 

 and April, while others are known from only a single or very few rec- 

 ords and are still accorded hypothetical status. One species, the Yellow 

 Warbler (Dendroica petechia) has both migrant and resident popula- 

 tions. Many of the migrant and wintering species join mixed flocks of 

 endemic birds, but some others become relatively sedentary while in 

 Panama and have been shown to maintain a territory. There is a strong 

 correlation between winter territoriality and retention of the "spring" 

 plumage; the warblers that have a less boldly marked basic plumage are 

 the ones that usually join mixed-species flocks. Many of the North 

 American species that are primarily insectivorous in the breeding sea- 

 son consume considerable amounts of fruit in Panama. 



Most of the resident wood warblers of Panama are found in the high- 

 lands: the three species of Geothlypis resemble G. trichas of North 

 America in behavior; a Vermivora and a Parula are highly arboreal, 

 usually foraging high in trees; the redstarts of the genus Myioborus 

 usually range in the lower levels of the forest; and the 5 species of 

 Basileuterus are found in forest undergrowth. Two wood warblers in- 

 habit the borders of streams and rivers rather like the waterthrushes 

 (Seiurus) of North America: Basileuterus fulvicauda is widespread 

 in the lowlands and foothills, and the Zeledonia, Zeledonia coronata, is 

 rare and local in forest streams in the highlands of Chiriqui and Ver- 

 aguas. Although Zeledonia has in the past been placed in its own family, 

 Sibley (Postilla, no. 125, 1968, pp. 1-12) and Raikow (Bull. Carnegie 

 Mus. Nat. Hist. no. 7, 1978, p. 28) have shown that it is an aberrant 

 parulid. 



KEY TO SPECIES OF PARULIDAE 



1. Throat or most of undersurface bright orange or yellow 

 Undersurface without bright orange or yellow 



2. Throat black, gray, or dusky 



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