The Breeding and Nesting of the Gray Catbird

BIRD COLUMN FOR August 22, 2004

By Benjamin P. Burtt

Topic: The Breeding and Nesting of the Gray Catbird Why does the male perch near the nest and flap his wings a lot?

Provided below is a copy of all the material that appeared in the newspaper column on the date above, plus extra information for the interested reader who wishes to learn more about this subject.

Here is a recent questionMr. Burtt: A pair of catbirds nests in my yard. One perches and flaps its wings for several seconds, then flies off, perches again and repeats the flapping. What is going on? W.M.-Cazenovia

CAPTION: The catbird is a gray bird with a black cap and an almost black tail. There is a distinctive rusty patch of feathers under the tail. See the arrows in this painting by Roger Tory Peterson in his "Field Guide to Birds of Eastern and Central North America". While the catbird is an excellent singer, it sometimes makes a cat-like mewing sound. (Courtesy of Houghton Mifflin Co.)

Dear W.M.: These motions are part of the way that the bird communicates with its mate and with other birds. Before we discuss the "wing flapping" and what it means, it will be helpful if I first review how birds do communicate.

How Birds Communicate
Making calls or songs
Making sound is the most obvious way that birds interact with each other. One of the types of sound we refer to as "song". This is perhaps a poor choice of words. Humans often sing to express a joyous or perhaps a sad feeling. Does the bird really feel those emotions?

When we carefully watch what birds are doing as they make these sounds, it is possible to get an idea of why they do it. It seems clear that male birds make "songs" when they are trying to attract a mate and when they are making an effort to keep other males away.

Sometimes people say a bird is scolding, but such noise is often made to announce to all other birds in the vicinity that a predator has arrived and is threatening a bird or its young. Other birds are attracted to the scene. When there is a large flock of different species diving at a predator and making lots of noise, the predator is less likely to capture even one for a meal.

Very young birds just out of the nest usually make sounds when they are hungry. A parent returning with food can easily find the hungry youngster. So the peeping sound is a means of communicating the baby's whereabouts.

Watching what birds do and how they interact with one another helps us learn what they are doing. It also adds a lot to our enjoyment of birds. However we really are not justified in attaching human-like emotions to the things birds do.

Communicating with body movements
In addition to making sounds, birds can communicate by body motion such as head bobbing, wing flapping or tail motion or fluffing the feathers. These have meaning to their mate and in some cases to other species of birds. Careful study and observation helps us understand why a bird makes a particular motion.

Activities in the Spring
The gray catbirds return from the Gulf states and Central America in the spring. The male selects an area as the territory where it will have its nest. Usually this is in a dense thicket. It sings loudly from various perches in that territory to tell other males that this area is taken and that females are welcome.

When other males come close there are disputes. Both males will make the cat like sounds at this time. Such disputes involve some chasing by the resident male. The chasing and mewing seems to settle the matter.

The mewing sound is also given when a predator is spotted. Whether it is threatening to the predator I do not know, but the sound will certainly alert the birds mate that there is some danger.

Imitates Other Birds

The catbirds singing is a sort of mixed song with lots of notes and phrases. It also sings the songs of other birds. It has been observed to sing the song of the bluejay, the quail, several different hawks, the whip-poor-will and even a tree frog.

In the Southern states it was often called the "black mockingbird".

Now for the wing flapping
The female catbird does all of the incubation. She stays on the eggs for about 20 minutes at a time. Then she leaves the nest for 5 to 10 minutes to feed.

During this time, the male must stay within a few yards of the nest, "guarding" it so to speak. How do these two birds coordinate this "changing of the guard?"

It would be dangerous for the eggs or the nestlings if both parents were away from the nest at the same time. Some means of communication is needed if the female is to leave the nest and have the male watch over it. Usually, she leaves after the male has approached and made a soft call accompanied by flicking his wings in and out from the sides.

While on "guard duty" within a few yards of the nest, the male continues to flick his wings. This may serve to distract an approaching predator away from the nest. When the female returns to settle on the nest, he goes off to feed nearby.

There is another wing motion that is used as an alarm signal. It indicates that you are approaching the nest or a predator has come in sight. In this case the catbird holds its head, body and tail all in a horizontal line. The wings are stiffly raised to the sides and held there a moment and then it is done again. What you described as "flaps its wings" may have been this "raised wings" motion repeated several times.

It would also help our interpretation of the behavior if we knew whether or not the female was on the nest at the time you observed the “flapping”. If she was there, the male was probably just indicating that he was nearby. It would also help if we knew whether you were visible to the bird that was flapping its wings. If you were observed, the wing motions were more likely a warning that you were there.

Another display involves the fluffing up of body feathers until the bird appears to be quite large. This is done by the male when another catbird is challenging him. The “fluffing” is also used if a snake or other predator approaches, the larger puffed up appearance is more threatening and helps to drive away the invader.

Books about bird behavior
After many hours of careful watching, the meaning of these sounds and motions is diagnosed. Scientists write down their observations and they are published in a scientific journal for others to read and study. When there is general agreement on the meaning of the behavior, someone will write a book about it.

If we wish to learn about the behavior of a particular bird, we must find such a book and look up the gray catbird as I did.

Donald and Lillian Stokes have written three books on bird behavior with each volume covering a different set of species. They have sketches that show some of the types of displays and the most probable meaning of each display.

They were written over a period of years and each one has the words “Bird Behavior” in the title. If you have observed some unusual behavior, you may find an explanation in the book that lists that species. Try your local library.

In addition to their Guides to Bird Behavior, the Stokes have written a series of Nature Guides on each of the following subjects: Insect Lives, Wildflowers and Animal Tracking. All of these are useful and available in a good library