To the Editor:

This spring I noticed what I did not hear in the morning hours — sounds of multiple birds greeting the dawn in my “tree street” neighborhood. It was the quietest spring I can remember. Each morning I heard two or three birds in the nearby trees. No mockingbirds, catbirds, or woodpeckers. It’s a huge change from when I first moved to Princeton.

While we worry about global warming, habitat loss, and large scale effects on our wildlife, there’s one very small thing that can be done to protect a huge number of birds — keep pet cats indoors. A recent study by the Smithsonian, published in the Journal of Ornithology, found cats were the number one killer of baby catbirds in the suburb studied. Cat predation was so serious, catbirds could not reproduce their numbers for a successive generation. The American Bird Conservancy has estimated that 500 million birds are killed by cats annually, split evenly between pets and feral cats. Other estimates also number in the hundreds of millions.

That seems like an impossible number. But assume your cat catches two birds per week. What’s two birds, right? Multiply those two birds by the 47 million pet cats allowed outside across the U.S. (estimated by The Smithsonian Conservation Biology Institute). That totals 94 million birds per week (not including the toll taken by feral cats.)

Once outside, your kitty’s a predator. We don’t have barns full of mice for kitty to stalk. We have small yards where songbirds, after arriving in the spring, nest and raise their young. Even well-fed cats enjoy stalking and are successful, especially on birds just out of the nest.

As an introduced species to our environment with few natural predators, the effects of cats on bird numbers shouldn’t be minimized or trivialized. Song birds face threats here, in wintering grounds, and during migration. But losses due to cats are easily within our power to ameliorate. If most of us keep our pet cat(s) indoors, we can cut losses dramatically. We can and should keep our own neighborhoods safe for birds to nest. Isn’t that the least we can do?

And outdoor cats themselves face many risks — traffic, dogs, wild animals, other cats, parasites, toxins, getting lost, etc. The American Humane Society recommends keeping cats indoors, purchasing prey-like toys, and rotating toys to avoid boredom. Outdoor time should be in a secured area, like a screened porch. Perches on window sills provide good entertainment viewing. Even paper grocery bags will engage your cat. Cats can have a great life indoors. After all, they are our pets, not wild animals.

It’s not enough to lobby government for conservation actions and press corporations for compliance with environmental laws. We need to police our behaviors and take responsibility for our effect on our planet. I urge cat owners to keep their cats inside. It’s a win-win. Cats and birds will both be safer.

Susan Betterly

Maple Street