I casually asked a physical therapist the other day, as she pushed on my spine, asked her if she had a cat. Yes. Did she let it outdoors? Yes. Did she know if the cat killed animals? Yes. The cat brought "bodies home to mama."

Earlier that week a report about birds and cats made news, not big news, but it was reported here and there, even on local TV. This study came from scientists at the Smithsonian Conservation Biology Institute in Washington, D.C. They had impressive numbers: an estimated four billion birds and 20 billion small mammals killed by North American cats each year. Feral and pet cats score big.

Some members of the birding community were upset with this latest in a line of studies all saying the same thing: cats kill. (They evolved to do that; it's their job.) The birding email lists hummed with links to the report and comment about it. Finally, other list members said enough already, and things went quiet.

Things always go quiet.

I told my editor that I wanted to write about the new report. I would interview and find a new hook for this old story. Well, there is no new hook. It's the same story. And the innocently uninformed and the ill-informed, those who don't know what's happening to birds? "Cats kill," the therapist said. "That's what they do."

We're not going to change the nature of cats. Birds will not suddenly evolve to live successfully with this invasive creature. (Cats are not native to North America, you know. They shipped with the Pilgrims, hopping ashore as the anchor dropped.) I'm not optimistic about convincing all cat owners to keep their pets indoors.

But, hey, the story made local TV! Cool! One of our television stations included a short bit on the cat report the day the it was published. A minute of film, a birdwatcher and his feeders, and two news anchors, all of whom said more than once that kitty kills cats, that kitty should stay indoors. Good job! Keep cats indoors, right there on the local news. And then one of the anchors fell off script, a few words of friendly chit-chat. Innocently uninformed chit-chat: maybe cats are doing us a favor otherwise maybe we'd have too many birds.

Too many birds. Thank you very much. And while you're up let the cat out.

The biggest outdoors story of the week was the announcement that Zebra Mussels have been found in Lake Winnibigoshish.

Hey! It's the same story! Cats are the Zebra Mussels of the mammal world! Invasive and almost impossible to control.

Or mention the permit being considered in southeastern Minnesota for construction of a wind farm. It would allow eight Bald Eagles to be killed annually by the world's biggest blenders.

Ask who's going to walk the site and keep the tally. How do you count dead eagles scavenged at night by raccoons? And what happens if you find eight piles of eagle feathers in the first five months of the year? No one is going to pull the plugs. Perhaps there would be fines, so much for each additional eagle. That will not help the eagles.

And so it goes. We are eating ourselves alive, and we like the flavor.

This is either a pet cat outdoors or a feral cat. Either way, it was beneath our birder feeders.