Wow, this one's hard to ignore. A new study conducted by Smithsonian Conservation Biology Institute and the Fish and Wildlife Service has greatly increased the estimated numbers of birds and other wildlife killed by domestic and feral cats each year in the U.S. The numbers are staggering. From the New York Times:

In a report that scaled up local surveys and pilot studies to national dimensions, scientists from the Smithsonian Conservation Biology Institute and the Fish and Wildlife Service estimated that domestic cats in the United States — both the pet Fluffies that spend part of the day outdoors and the unnamed strays and ferals that never leave it — kill a median of 2.4 billion birds and 12.3 billion mammals a year, most of them native mammals like shrews, chipmunks and voles rather than introduced pests like the Norway rat.