pet connection

A couple years ago I sent a note to Carl Bialik, the Wall Street Journal’s ‘Numbers Guy’ columnist, asking him to look at a commonly used figure regarding feline reproduction.  Here’s what I wrote about what he found out:

After getting yet another fund-raising pitch from a humane organization citing the “fact” that a single female cat can be responsible for producing 420,000 more cats in seven years, I asked The Wall Street Journal’s “Numbers Guy,” Carl Bialik, to do the math.

It turns out that although feline overpopulation is a real problem, cats simply cannot multiply as exponentially as many humane groups say. After talking to veterinarians about feline reproduction and mathematicians about probabilities, Bialik came up with a range from 100 to 5,000 for the offspring of a single cat—either way, a far cry from 420,000. If cats truly reproduced that quickly, notes Bialik in his piece on the Journal’s Web site, then in the 18 years since that figure first popped up in a newspaper, there’d be 50 trillion cats today. (Best estimates: 90 million pet cats and 70 million ferals.)

Well, of course, shelters still use that number, and it’s a pretty good bet that people are still going to keep using that old “one ‘dog year’ equals seven ‘people year’” nonsense, too. But in the interest of getting the facts straight, Bialik called me as part of his story on how “dog years” really add up. Here’s what he writes on his WSJ blog:

Veterinary researchers have long known that dogs age quickly after birth, and that aging varies by breed, but the seven-year rule persists.

Brian Kenny, a Phoenix anthropologist and dog owner who maintains the myth-debunking site Dog Years thinks he understands the impulse from his own field. “It’s a typical thing in anthropology,” Mr. Kenny told me. “We have complex ideas of how the world works. We see a lot of data pass before our eyes. Often to make it simplified for the public, we come up with a normative concept to help people relate.”

But there is no one-size-fits-all rule for dogs. “Dogs are the most diverse domestic species we have,” Gina Spadafori, syndicated pet-care columnist with Universal Press, told me. “We have cut and tailored and bred them in so many different forms. They’re all the same species, but they’re hardly recognizable as such.”

If you’re a WSJ subscriber, you can read the full article, here.

(And speaking of old dogs, the picture is of Heather, earlier this evening. )