BIRDS OF NEW YORK 69 



the daily movements of these birds to and from their feeding grounds with 

 their migratory movement. 



Another indication of the trend of a bird route is the abundance of 

 species and individuals in the country traversed, and when sufficient data 

 are at hand is as infallible a guide as the flights of day migrants. There 

 is abundant evidence to show that birds are far more numerous during 

 both the spring and fall migration along the coast, in the Hudson valley 

 and along the southern shore of Lake Ontario, than they are on the 

 highlands in western and eastern New York. 



A third and very important guide to these bird routes is the distribu- 

 tion of species which are not found in every portion of the State. For 

 instance there can be little doubt that the Cerulean warblers which breed 

 in western New York enter that region from the west, or southwest, where 

 that species is found both in the lireeding and migration seasons. The same 

 is true of the Migrant shrike and Prairie homed lark which originallv invaded 

 New York from the west and still each season return on their migrations 

 along the route which was slowh- established 1)\- their ancestors. The 

 Orchard oriole, Grasshopper sparrow, and Louisiana water-thrush, which 

 are common in the vicinity of New York city and are also found as far 

 north as Lake George but are not common in the Mohawk valley, undoubtedlv 

 travel b)' the Hudson valle}' route in their yearly migrations, as is also 

 true of many other species. The Yellow-breasted chat, which is rare in 

 the \-icinity of Lake Erie, Lake Ontario and the Mohawk valley, but is 

 fairh' common near Binghamton, Elmira, and the southern ends of the 

 Finger Lakes, undoubtedly finds its way up the Delaware and Susque- 

 hanna valleys, as does the Kentucky warbler which breeds as far north 

 as Cincinnatus, and the Carolina wren which has bred at Ithaca. There 

 is no doubt that the Adirondack birds arrive both by the Hudson and the 

 Ontario routes; those of the western and northern portions coming 

 by wav of the southern shore of Lake Ontario, where all the species 

 common in the western Adirondacks are abundant in migration time, 

 while those of the eastern Adirondacks come b\- wav of the Hudson vallev. 



