Catbirds in Trouble

A birder’s favorite bird is usually the last one they’ve happened to see, but I have a particular fondness for the catbird, a dapper little figure in gray with a little black top hat for both males and females. He’s a relative of the mockingbird whose pitch perfect imitation of other birds is legendary. Catbird’s imitate too, but there’s a little bit of the rusty gate in its songs as well as the characteristic cat-like meowing. This doesn’t stop the catbird from singing from the highest perch he can find in the thickets and shrubs that are his home, and the term “sitting in the catbird’s seat” comes from this habit. At all times catbirds are pert, inquisitive and peppy, and today this happy little bird is in trouble.

 The Smithsonian's Migratory Bird Center published a summary of a study of Catbirds in suburban Maryland. The study took place in three parks in towns with two population densities a little larger and one a little smaller than Easton. While studies have often looked at nest success (something we do with our bluebirds at Sheep Pasture), the catbird study followed the juvenile birds into the post fledgling period. A fledgling is a young bird who can fly a little and who has left the nest. Mom and Dad typically feed the fledglings for a few days outside the nest while they learn the ropes of being a bird. With catbirds the fledgling/post fledgling stage is rather spectacular as the juvenile birds hide in bushes and make plenty of noise to attract the parents with a free lunch.

The baby birds had been fitted with radio transmitters so that they could be tracked after they left the nest. About half the fledglings made it to adulthood in one park while only 10% did so in another. Predators accounted for 79% of the fledgling mortality overall with the highest rate of predation in the first week after leaving the nest. Now lots of things eat fledglings including other birds especially blue jays and crows and native mammals like squirrels and chipmunks. However, in two parks more than half  the fledglings were killed by cats. One can conclude that native birds have not adapted well to this introduced predator. The study notes that high quality habitat helps reduce predation.

What are the lessons for Easton? Stricter laws regarding cats would help. Why do these damaging predators roam free? Given that coyotes seem to find domestic cats delicious, why do owners let their cats out alone anyway? At places like Sheep Pasture feral and semi-feral cats should be removed and sent to a no-kill shelter. Attention should also be given to providing quality habitat so that a property  does not become a reproductive sink where birds find it easy to nest, but hard to raise babies to adulthood. Studies by professional forester Phil Benjamin and wildlife expert Diane Boretos tell us that Sheep Pasture has a exceptional variety of habitats that can be managed to balance the needs of wildlife with the needs of visitors, but, for me, the needs of wildlife should have more weight in the scales.