MUSEUM OF COMPARATIVE ZOOLOGY. 421 



widely, as is well known, in respect to the extent of their migrations. 

 Those of a few families (as the TdraonidcE, the Picidce, Sittidee, Cor- 

 vidce, and Strlyidce) are nearly sedentary, the nature of their food 

 being such that the supply is almost equally sure at all seasons. The 

 insectivorous species have the most extended migratory range ; the pis- 

 civorous, the graminivorous, and the raptorial the least of the non- 

 sedentary species, the migrations of the latter being mainly governed 

 by those of their prey. Hence the wood warblers {Sylvicolidce), the fly- 

 catchers (Tyrannidce), and the swallows make the longest journeys, and 

 leave their breeding stations the earliest. Requiring apparently a 

 temperature in winter similar to that of their summer habitats, as well 

 as a constant supply of insect food, they begin their southward journeys 

 almost before the close of the short northern summer, proceeding grad- 

 ually southward during the autumn months to pass the winter in the 

 tropics. The Grallce have also to seek districts almost wholly beyond 

 the reach of severe frosts, their food being only accessible to them 

 where the ground continues unfrozen. The Natatores also necessarily 

 migrate to localities where the streams and estuaries are nearly free 

 from ice ; the strictly littoral and pelagic species hence making shorter 

 journeys than the inland species. 



The migratory insessorial birds that pass the winter wholly or in 

 part within the Eastern Province are principally fringilline species. 

 The others are a single flycatcher (Sayornis fuscus), the northern 

 members of the Icteridce, two species of Tardus, three of Mimince, 

 three wrens, and three or four sparrows. All of these species are 

 resident the whole year in those sections to which the northern mem- 

 bers of these species mainly resort in winter. In these species there 

 is hence only a partial recession southward in winter from the northern 

 portions of their respective summer habitats. Most of the Frinyillidce, 

 however, which pass the summer within or to the northward of the 

 Alleghanian Fauna, remove wholly in winter from- their summer sta- 

 tions. "While some in winter barely abandon their summer stations, 

 as shown in the preceding tables, of distribution, others pass entirely 

 over one fauna, throughout which they occur only as spring and au- 

 tumn passengers ; others in a similar way pass over two fauna? in 

 reaching their winter quarters. Hence some which breed in the Cana- 

 dian Fauna and farther northward pass only into fhe Alleghanian and 

 Carolinian Faunas in winter, while others pass over the Alleghanian 



