EXTENT OF ISnGRATION". 49 



Extent of Migration. — Tlie extent of a bird's migra- 

 tion is, in most cases, dependent upon the natui-e of its 

 food. Birds that are resident in one place throughout 

 the year generally change their fare with the season, 

 and apparently feed with equal relish on seeds or insects. 

 Those that are dependent npon fruit must migrate far 

 enough to find a supply of berries, while the insect-eaters 

 are obliged to travel even farther south. 



Most of the migratory birds of our Western States 

 pass the winter in Mexico. Our Eastern Sparrows and 

 our berry-eaters, like the Robin and Blueljird, winter 

 from the Middle States to the Gulf coast, while the ma- 

 jority of our purely insectivorous species cross to Cuba 

 and winter in the AVest Indies, or continue to Central 

 America and even northern South America. Snipe and 

 Plover make the most extended migrations, some species 

 breedino; within the Arctic Circle and wintering: alone: 

 the coasts of Patagonia. 



Thnes of Migration. — Let us suppose we are about 

 to observe the spring migration of birds at Englewood, 

 New Jersey — a few miles from JN^ew York city. Birds 

 arrive here about a week later than at Washington, D. C, 

 and a week earlier than at Boston. 



During January and February, while watching for 

 some rare visitor from the Xorth, we shall find that Tree 

 Sparrows and Juncos are everywhere common. Less 

 frequently we may see Shrikes, AVinter Wrens, Golden- 

 crowned Kinglets and Brown Creepers, and rarely Snow- 

 flakes, Ped Crossbills, and Pedpolls will be observed. 

 These birds are winter visitants, coming to us from the 

 North in the fall and lea\ang in March and April. 



Of course, in addition to these migratory birds, we 

 shall see most if not all of our connuoner permanent 

 residents, or the birds which are with us throughout the 

 year. They are the Bob-white, Ritffed Grouse, Ped- 



