How many passenger pigeon were there?

Answer 1

It is believed that this species once constituted 25 to 40 per cent of the total bird population of the United States. It is estimated that there were 3 billion to 5 billion passenger pigeons at the time Europeans discovered America. However, the Passenger Pigeon is now extinct. Over hunting, the clearing of forests to make way for agriculture, and perhaps other factors doomed the species. The decline was well under way by the 1850's. The last nesting birds were reported in the Great Lakes region in the 1890's. The last reported individuals in the wild were shot at Babcock, Wisconsin in 1899, and in Pike County, Ohio on March 24, 1900. Some individuals, however, remained in captivity. The last Passenger Pigeon, named Martha, died alone at the Cincinnati Zoo at about 1:00 pm on September 1, 1914.

Answer 2

There were probably millions and millions because I heard that the passenger pigeons could practicaly cover the skies so it's really hard to believe that they are extinct.