In the 18th century, the passenger pigeon in Europe was known to the French as tourtre but, in New France, the North American bird was called tourte. Martha, thought to be the world's last passenger pigeon, died on September 1, 1914, in Cincinnati, Ohio. There was a slow decline in their numbers between about 18, followed by a catastrophic decline between 18. The primary factor emerged when pigeon meat was commercialized as a cheap food for slaves and the poor in the 19th century, resulting in hunting on a massive scale. Some reduction in numbers happened because of habitat loss when the Europeans started settling further inland.
At the time, passenger pigeons had one of the largest groups or flocks of any animal, second only to the Rocky Mountain locust. The species went from being one of the most usual birds in the world during the 19th century to extinction early in the 20th century. Others argue that the species had not been common in the Pre-Columbian period, but their numbers grew when devastation of the American Indian population by European diseases led to reduced competition for food. Some estimate that there were three billion to five billion passenger pigeons in the United States when Europeans arrived in North America. It lived in enormous migratory flocks - sometimes containing more than two billion birds - that could stretch one mile (1.6 km) wide and 300 miles (500 km) long across the sky, sometimes taking several hours to pass.
The passenger pigeon, or, wild pigeon was a species of bird, Ectopistes migratorius, that was once common in North America. The passenger pigeon ( Ectopistes migratorius) or wild pigeon was a species of pigeon that was once the most common bird in North America.