184 Bulletin American Museum of Natural History. [Vol. XXXVI, 



Twelve of these axe water-birds of which nine are shore-birds; while of the 

 thirty-three land-birds fourteen are Warblers. Of the whole number only 

 one, the Western Wood Pewee, is a bird of the western United States; two, 

 Grinnell's Water-Thrush and the Dickcissel, are birds of the interior of 

 North America, while most of the remaining species are birds of the 

 Atlantic slope. 



Our dates of captiu^e are, as a rule, during the season when the species 

 might be expected to occur. We have, however, two Barn Swallows, one 

 collected on the Bogota Savanna, May 13, 1914, and a second taken at 

 Quibdo, August 20, 1912. The first date is a month later than the species 

 reaches the altitude of New York; the second is more than a month earlier 

 than that of the final departure of the species from the same latitude. 



So far as our observations go, they indicate that the range in Colombia 

 of these winter visitants from North America is not confined by the zonal 

 boundaries which exercise so strong an influence over the distribution of 

 permanently resident species. The Yellow-billed Cuckoo, Olive-backed 

 Thrush, Yellow Warbler, Blackburnian Warbler, Mourning Warbler, and 

 Rose-breasted Grosbeak all range from the Tropical to the Temperate Zone; 

 the Black-and-White Warbler, Golden-winged Warbler, Grinnell's Water- 

 Thrush, Wilson's Warbler and Redstart were taken in both the Tropical 

 and Subtropical Zones. 



Faunal boundaries are also disregarded. Nor does the land connec- 

 tions between northwestern Colombia and Central America exert any very 

 evident influence on the distribution of North American migrants in Colom- 

 bia. The Bay-breasted Warbler was common in the Choco region and lower 

 Cauca-Magdalena Fauna, and was not found east of the Eastern Andes; 

 but, with this exception, migrants appeared to be as common in the Eastern 

 Andes as in the Western or Central Andes. Ten of the fourteen Warblers 

 taken, for example, were collected on the eastern slope of the Eastern Andes. 



There is, therefore, no indication that the Isthmus of Panama is a 

 causeway over which North American migrants enter South America. 

 Indeed, so far as Colombia is concerned. Dr. Allen's paper on the North 

 American migrants found in the Santa Marta region (The Auk, XVII, 

 1900, pp. 363-367) suggests that this mountain promontory is the port of 

 entry. 



List of North American Migrants. 



Porzana Carolina Helodromas solitarius 



Charadrius dominicus dominicus Actitis macularia 



iEgialites semipalmata Tringa minutilla 



Totanus melanoleucus Pisobia maculata 



" flavipes Gallinago deHcata 



