Plan B Forum

What's interesting is the source of the graphic-- the National Shooting Sports Foundation, a weapons industry association-- and the reason that the NSSF put it together: to fend off criticism of lead ammunition, which is fatally ingested by a lot of raptors and waterbirds and is threatening to drive the California Condor back into extinction in the wild. Alternatives to lead exist, but, owing to low production of them, they're currently somewhat more expensive.

What's striking about the pie chart is how big a slice of it consists of predation by free-roaming cats. A large new peer-reviewed study published in 2013 estimates the number of North American birds killed by cats at well over one billion per year. Bells on collars don't help. Neutering feral cats doesn't work. Keeping cats indoors helps.

Jonathan Franzen is the author of the novels The Corrections and Freedom. His most recent book is The Kraus Project, an annotated translation of essays by Karl Kraus.

Cats kill more than one billion birds each year
New estimate suggests hunting felines take bigger bite than expected out of wildlife
by Susan Milius
5:35pm, January 29, 2013
Magazine issue:
February 23, 2013


Domestic cats kill many more wild birds in the United States than scientists thought, according to a new analysis. Cats may rank as the biggest immediate danger that living around people brings to wildlife, researchers say.

America’s cats, including housecats that adventure outdoors and feral cats, kill between 1.4 billion and 3.7 billion birds in a year, says Peter Marra of the Smithsonian Conservation Biology Institute in Washington, D.C., who led the team that performed the analysis. Previous estimates of bird kills have varied, he says, but “500 million is a number that has been thrown around a lot.”

For wild mammals, the annual toll lies between 6.9 billion and 20.7 billion, Marra and his colleagues report along with the bird numbers January 29 in Nature Communications. The majority of these doomed mammals and birds fall into the jaws of cats that live outdoors full-time with or without food supplements from people.

“The results are remarkable, not only for the big number, but also for the proportion of deaths from feral cats,” says Gary M. Langham, chief scientist for the National Audubon Society. The study assigns 952 million to 3.1 billion bird deaths a year to these wild cats. “These numbers really elevate this threat to a new level.”

To figure out how much wildlife cats catch, Marra and his colleagues combed the scientific literature for the best assessments of how many cats live in the United States and of what cats there and in similar climates hunt. Roughly 114 million cats live in the contiguous United States, 84 million of which share people’s houses. Forty to 70 percent of those household cats do at least some roaming outside. Between half and 80 percent of those outdoor cats hunt.

to fend off criticism of lead ammunition

Long Run wrote:And how few die of natural causes!