Cats are one of the top threats to US wildlife, killing billions of animals each year, a study suggests.
The authors estimate they are responsible for the deaths of between 1.4 and 3.7 billion birds and 6.9-20.7 billion mammals annually.
http://www.bbc.co.uk...onment-21236690
And in the USA Today
http://www.usatoday.com/story/news/nation/2013/01/29/cats-wild-birds-mammals-study/1873871/