282 THE SLAUGHTER OF NORTH AMERICAN BIRDS 



The 'practical extermination of a species means the destruc- 

 tion of its members to an extent so thorough and wide-spread 

 that the species disappears from view, and living specimens 

 of it cannot be found by seeking for them. In North America 

 this is to-day the status of the whooping crane, upland plover, 

 and several other species. If any individuals are living, they 

 will be met with only by accident. 



The absolute extermination of a species means that not one 

 individual of it remains alive. Judgment to this effect is 

 based upon the lapse of time since the last living specimen 

 was observed or killed. When five years have passed with- 

 out a living "record" of a wild specimen, it is time to place 

 a species in the class of the totally extinct. 



Extermination in a wild state means that the only living 

 representatives are in captivity or otherwise under protec- 

 tion. This is the case of the heath hen, and David's deer, of 

 China. The American bison is saved from being wholly 

 extinct as a wild animal by the remnant of about three hun- 

 dred head in northern Athiabasca, and forty-nine head in the 

 Yellowstone Park. 



The extermination of the birds of North America began 

 A. D. 1800, when whalers attacked the great auk for its oil, 

 and clubbed that species out of our avifauna. The next 

 important step concerned the passenger pigeon; but in the 

 West Indies other species were swept away so quickly and so 

 thoroughly that we scarcely learned of their existence until 

 they were extinct. It is of historic interest to record here a 

 list of the species of North American birds that have become 

 totally extinct during our own time. 



