476 FAMILY COLUMBIA, OR PIGEONS. 



countries, there are none more remarkable than the Passenger- 

 Pigeons of North America ; the multiplication of which is so 

 rapid, and their destructive power so great, that they are obliged 

 to migrate from place to place in vast flocks, to obtain their food. 

 These flocks are often so extensive, that they occupy three hours 

 in passing any given spot ; and as the Birds fly with great 

 rapidity and steadiness, their rate is probably not less than sixty 

 miles an hour ; from which the length of a single flock must be 

 J80 miles. It has been calculated by M. Audubon, that the 

 number of individuals in one of these enormous flocks, estimating 

 its breadth at a mile, and allowing two Pigeons to each square 

 yard (which is rather within than beyond the mark), amounts to 

 1115 millions; and that as each Pigeon daily consumes fully 

 half a pint of food, the quantity necessary for supplying this 

 multitude must be 8,712,000.bushels per day. When it is stated, 

 also, that great numbers of such flocks often follow one another, 

 darkening the air for several days in succession, the wonder is, 

 not that they should do great injury to the agriculturist, and 

 should be dreaded by him as a pest, but that they should any- 

 where find a sufficient supply of nutriment. Their breeding- 

 places are described as large forest-tracts, fifty miles in length, 

 by four or five in breadth; in which every tree is occupied by 

 from fifty to a hundred nests. Allied to the true Pigeons on one 

 side, but presenting more points of resemblance to the Insessores, 

 are the Tree-Pigeons of Asia, Africa, and Australia ; they have 

 long wings, and live among trees, feeding on fruits and berries. 

 And, on the other side are the Ground-Doves^ which have 

 short rounded wings, and which are mostly seen on the ground 

 seeking for grains and seeds ; these are inhabitants of both 

 hemispheres. 



429. To this group also the recent researches of Naturalists 

 have led them to refer a curious bird which, although living 

 within the last two hundred years, has now been so completely 

 extirpated from the face of the earth, that our only knowledge of 

 its external appearance is derived from a few pictures, and of its 

 zoological characters from a few fragments preserved in two or 

 three museums. This is the Dodo (Fig. 270), which was very 



