Extinction

The passenger pigeon, once the most abundant bird in North America, was a boom or bust species, depending on the availability of food and habitat. At its peak, the population was estimated to be 3 billion birds. 

But the pigeons were highly valued for their meat and feathers, and over a span of just 50 years the species faced extinction. Refrigeration, railways, commercial food production, and deforestation all contributed to their end. 

Today, scientists are attempting to revive the passenger pigeon, along with other iconic species such as The Woolly mammoth and the Dodo, through the process of de-extinction. There is ongoing debate regarding the feasibility of resurrecting a true passenger pigeon, as well as ethical concerns surrounding the process.