One of the biggest threats to native birds is outdoor cats. In fact, based on a groundbreaking study by scientists from the Smithsonian Conservation Biology Institute and the U.S. Fish and Wildlife Service, it is estimated that outdoor cats (feral and pets that are allowed to roam freely) kill approximately 2.4 billion birds every year and are the leading source of direct, human-caused mortality to birds in the country.
This is often a controversial topic, as many bird-lovers are cat-lovers too, but the science is clear. Cats are responsible for the extinction of bird species worldwide.
Photo by Vasily Vishnevski