46 THE PASSENGER PIGEON IN PENNSYLVANIA 



that twenty millions of adult birds had been in that 

 region in 1810 ; or at any other time. To them it was 

 romance. In February, 1810, the groat flight into Ohio 

 and Indiana, where they nested in April and ^lay of 

 that year, was reported by Alexander Wilson who ap- 

 proximated their number in the following manner : 

 Taking the breadth of the great column of pigeons 

 that he described flying over the Oliio river to be only 

 one mile, its length to be two hundred and forty miles, 

 and to contain only three pigeons in each square yard, 

 (taking no account of the several strata of birds, one 

 above the other), and that each bird consumed half a 

 pint of food daily, the amount would oe seventeen mil- 

 lion bushels of food for each day. 



John J. Audubon made a calculation, based upon 

 two birds to the square yard, and a smiilar daily ra- 

 tion for each bird, in his report, u^ing approximately 

 the same breadth and length of the column — all of 

 which assumptions he believed to be conservative — 

 and estimated that eleven million bushels of food would 

 be required by them for one day. This means four- 

 teen hundred millions of birds in the Green river 

 flights ; about an equal number upon Kentucky river, 

 at the same time ; and the flight to Ohio and Indiana, 

 ir February, twenty-one hundred and. seventy-six mil- 

 lions more, making altogether, nearly five billions of 

 birds in the three states along the Ohio. Some people 

 consider these estimates as absolutely poetical, or 

 founded upon a "poet's license," at any rate. 



The authors were absolutelv candid, in all their 



