By Susan Milius
Passenger pigeons, so abundant during the early 19th century that skies darkened with passing flocks, may often have been nothing special in numbers during much of their last million years.
DNA from the extinct species, coaxed from toe pads of three museum specimens, suggests that population numbers fluctuated in the long term. The breeding population could have been at times only roughly several hundred thousand or even just tens of thousands of birds, says Chih-Ming Hung of National Taiwan Normal University in Taipei.