Cats could be the leading cause to the decline of the wild bird population.
According to USA Today, cats kill 1.4 to 3.7 billion birds a year in the U.S.
These numbers add to the tension between cat and bird lovers.
"The issue is not cats vs. birds but "a runaway and invasive population of cats" that are killing too many birds,"
American Bird Conservancy president George Fenwick explained.
Becky Robinson, president of the outdoor cat defense group Ally Cat Allies, simply said, "This is not Sophie's Choice; this is not the American people voting to kill one animal over another."
Aside from killing birds, cats are responsible for the killing of 6.9 to 20.7 billion mammals, including mice, shrews and rabbits.
A proposed solution is the Trap-Neuter-Return policy, which will reduce outdoor cat populations and help to avoid extreme euthanasia of outdoor cats.