In our report below - on cats and birds - we stated that the study was conducted by the U.S. Fish and Wildlife Service. To clarify, it was a joint study with The Smithsonian Conservation Biology Institute.
A new study by the U.S. Fish and Wildlife Service and The Smithsonian Conservation Biology Institute doesn't mince words: Cats, it says, are bird killers. In the U.S. alone, they're responsible for the deaths of up to 3.7 billion birds every year. NBC's Brian Williams reports.