CHAPTER IX. 



THE DESTINATIONS OF THE MIGRANTS. 



The Great Summer Quarters of Migratory Birds— Limits of 

 Pal^arctic and Nearciic Regions — Their Comparative 

 Avifaunas — Reasons for Poorness of Nearctic Avifauna — 

 Winter Quarters of PaLnearctic Migrants— Winter Zones 

 of West Palaearctic Birds — Winter Zones of East Palsearctic 

 Birds— Comparison of Winter Range of East and West 

 Palcearctic Species — Influence of Gulf Stream on Geo- 

 graphical Distribution and Migration of Birds — CHmate 

 of Nearctic Region— Effects on Migration — Winter Zones 

 of Nearctic Migrants— Bird Life m the Southern Zones 

 daring Winter— Winter Quarters of Southern Hemisphere 

 Migrants— Northern Sea Flights— Isothermal Lines of 

 Temperature — Temperature and Breeding-Grounds — Effects 

 of Varying Temperature on Birds — Our Knowledge of the 

 Geographical Distribution of Birds yet rudimentary. 



Every regular migrant has a definite Winter Home. 

 At one end of its fly-line the usual breeding- 

 grounds are situated ; at the other end the locality 

 where it spends the winter, or, as in the case ot 

 a very great number of instances, the place where 

 it enjoys all the luxury of a second summer. To 

 make no allusion to these northern and southern 

 destinations in a work devoted exclusively to the 

 Migration of Birds would be an unpardonable 

 omission. 



