The largest range of any species is that of the rock dove. This species had a large natural distribution from Britain and Ireland to northern Africa, across Europe, Arabia, Central Asia, India, the Himalayas and up into China and Mongolia. The range of the species increased dramatically upon domestication, as the species went feral in cities around the world. The species is currently resident across most of North America, and has established itself in cities and urban areas in South America, sub-Saharan Africa, Southeast Asia, Japan, Australia, and New Zealand. The species is not the only pigeon to have increased its range due to the actions of man; several other species have become established outside of their natural range after escaping captivity, and other species have increased their natural ranges due to habitat changes caused by human activity. A 2020 study found that the East Coast of the U.S. includes two pigeon genetic megacities, in New York and Boston, and they don't mix.