The decline and extinction of the passenger pigeon is one of the saddest chapters in natural history. When Europeans first arrived in North America passenger pigeons thrived in the billions. In 1800 they were so plentiful that a pair could be bought for just two cents. They lived in enormous flocks that sometimes overspread 300 square miles. However, by the mid-1800s, loss of habitat and the demand for a cheap source of meat doomed the passenger pigeon to extinction. The last accepted wild passenger pigeon was spotted in 1900. The last passenger pigeon in captivity, a female named Martha, died in the Cincinnati Zoo on September 1, 1914.