Lists of American Birds. 177 



CHAPTER VIII. 



Directions and Causes of the Migrations of the Birds of Boreal America, 

 and Laws bearing on Variation of Species — Ducks Building in Trees — 

 Abnormal Habits of Animals — Celibacy among Birds — Strange Habits 

 of the Great Northern Diver — Attachment to its Young — A Loon 

 Hunt — Reptiles — Turtles — Snakes — Frogs — Tritons. 



ALTHOUGH for the last half century naturalists have 

 directed their attention to the study of the birds of the 

 New World, it is only of late years that zoological geography 

 in general has been prosecuted with the amount of care and 

 research its importance deserves. In America, Wilson and 

 Audubon paved the way towards an accurate knowledge of 

 the species, and subsequent observers added to the rich stores 

 accumulated by them. When Prince Charles Lucien Bonaparte 

 published his geographical list of the birds of Europe and 

 Northern America, in 1838, he computed the number of 

 species of North American birds at 471, whilst the latest 

 census, made by Professor Baird,* raises the number to about 

 680, exclusive of species common to the Old and New Worlds. 

 Since the latter list was published, many new species have 

 been added ; for whilst the birds of the United States, and 

 the eastern portion of the Canadian dominion, are now' well 

 known, those of the Pacific side of the continent, Mexico, and 

 the Arctic Regions have not been fully determined. 



Turning to our chief subjects of inquiry, it must be apparent 

 that an accurate knowledge of the ornithology of the neigh- 

 bouring countries is requisite in determining the distribution 

 and migrations of the birds of New Brunswick ; accordingly, 



* " Report on the Birds of the United States," Pacific Railway Report. 



N 



