The Passenger Pigeon, which numbered once in the tens of billions, lived in North America east of the Rocky Mountains.
Their flocks, a mile wide and up to 300 miles long, were so dense that they covered the entire sky for hours as the flock passed overhead.
Population estimates from the 19th century ranged from 1 billion to close to 4 billion individuals.
Total populations could well have reached 5 billion individuals and the passenger pigeon comprised about 40% of the total number of birds in North America.
This may be the only species in the entire world for which the exact time of extinction is known down to the moment it happened.
The Passenger Pigeon was similar to but larger than the Mourning Dove.
It was slate blue on its head and bottom, a gray back and a lovely wine red breast.
Male coloration was deeper and brighter than the female. The eye was scarlet.
The short, black bill, slender in its makeup was well suited to the diets the birds ate, which were acorns, beechnuts, chestnuts, various fruits, grains and insects.
Tens of thousands of individuals were harvested daily by hunters, who hunted into their nesting colonies and shipped them to markets to be processed.
Our very advances in technology helped to speed the death and extinction of this beautiful bird
The telegraph would help to spread where the locations of flocks could be ascertained, and the birds were hunted relentlessly, then modern shipping saw to their shipment for markets
A remarkable bird, all estimates say that the passenger pigeon could reach speeds of 70 miles per hour and sometimes faster.
The last Passenger Pigeon, Martha, died completely alone at the Cincinnati Zoo at about 1:00 pm on September 1, 1914.