Cats Responsible for Billions of Deaths.
Hunters have long known feral cats and pet cats allowed outdoors pose a problem to native wildlife. Now, according to a study authored by scientists from the Smithsonian Conservation Biology Institute and U. S. Fish and Wildlife Service and published by Nature Communications, an online research journal, it is thought that outdoor cats are responsible for the deaths of birds and mammals by the billions. Though the damage was previously thought to be much less, the study found the annual bird mortality rate from cats is now estimated to be between 1.4 billion to 3.7 billion, and the mortality rate for mammals is a staggering 6.9 billion to 20.7 billion.
The study determined that 67 percent of birds and up to 100 percent of mammals preyed upon by cats are native species. The mass removal of these prey items from the food chain dramatically reduces the available food source for native animals such as foxes, bobcats, and birds of prey. Cats also raid the nests of upland birds and small game, thereby reducing birth and survival rates. Furthermore, accoridng to The Birding Wire, free-ranging cats on islands have caused or contributed to 14 percent of modern bird, mammal and reptile extinction. Current policies for management of free-ranging and outdoor cats focus on animal-welfare issues such as trap-neuter-return efforts, but do not address the destructive ecological impacts. If we want to conserve native birds and mammals, including many game species, perhaps it's time cat-management efforts focus on permanent removal from wild ecosystems.