While I usually appreciate Diane Pleninger’s insights and perspectives, she’s got it wrong when it comes to cats and birds (“Cats kill tiny percentage of birds,” Feb. 4). The New York Times article referred specifically to the domesticated feline toll on birds in the U.S., while the number Pleninger uses, 400 billion birds, is a worldwide estimate.

According to several online sources that I checked, the best estimate for U.S. land birds is 10 billion in the spring and 20 billion in the fall (after nesting). So if free-roaming cats are killing an estimated 2.4 billion birds annually, that means they’re removing more than 10 percent of the population. Contrary to what Pleninger argues, this is a large and unacceptable toll.

Free-roaming cats are a huge problem, but the bigger problem is the people who let cats run free.

— Bill Sherwonit

Anchorage