Cats as rat control? Not in New York

New York rats are big and bad. They sit calmly on the subway tracks, ignoring discomfited commuters on the platform. They stroll through Central Park as if they owned the place. They pretty much rule the East Village.

And they do not have much to fear from cats, a new study suggests.

In the report, published in Frontiers in Ecology and Evolution, the authors first present some background. Cat predation of rats has been studied

before: Researchers in New Zealand, for example, analyzed scat from 229 cats and learned that almost all of them ate rats. The felines even seemed to prefer rats to birds.

But New Zealand rats weigh an average of 150 grams, whereas rats in the most recent experiment in New York were more than twice as large. Bulk, it turns out, is an obstacle for cats who might otherwise dine on city rats.

It was not easy for the scientists to find a place to do their research. The lead author, Michael H. Parsons, a research bi-

ologist at Fordham University, said property owners generally want their rats killed, not caught and then released for study. But the team eventually found a recycling plant in Brooklyn whose staff were willing to let the rat detectives do their work.

While the researchers were watching these rats, five feral cats took up residence at the plant, so the team seized the opportunity to study them, too.

Parsons used motion-sensitive video cameras to record cat behaviours in the presence of rats — walking, running, stalk-

ing, chasing, feeding and so on. They made 306 videos over three months.

All the cats stalked rats, but only two even dared to chase and attack a rat. Each made just one kill.

When cats appeared on the scene, rats mostly just hid. For every 1-per-cent increase in the number of cat appearances per day, rats were 100 times less likely to trigger a camera. Apparently New York rats are not only large and bold, but smart and stealthy.