Robins starting to sing, define their territory
We heard the male robin in our backyard begin singing on the March 10. On March 22, a late-arriving male robin came on the scene and attempted to also set up his territory in our backyard.
The second robin, who did not heed the first robin’s warning to stay out of his territory, was quickly chased away
Usually, in the spring, a bird sets up a breeding territory and defends this territory against other males. At the same time, he tries to attract one or more females to share his territory. This defined area ensures the bird family will have food, cover and a nesting site. The male and female robins return to the same area each year, and if mated the previous year, there is a good chance that they will pair up again. It is possible that the female robin will build her nest in either the same tree or on top of nests from previous years.
Protecting a territory is no easy task, with the males finding themselves in constant battles with other males. Usually, the larger the bird, the larger the territory. However, the size also depends on food and cover conditions and population of the particular species of bird.
The average size of a robin’s territory is about one-half acre. Of course, this all depends on the robin population and the food supply. The first male robin to arrive in the north often tries to stake out a large territory. As more and more robins stream north, the size of the territory shrinks.
A bird will defend the center of its territory more aggressively than the outer edges. Most of the time, the bird defending the territory will win the conflict, especially if the fight takes place near the center of his territory. If a male robin is disposed of from his territory, which rarely happens, the female does not leave with him but accepts the winner. Evidently, the females are attracted more to the territory than to the male. What would a summer day be without hearing the birds sing?
Although the male bird is usually the singer, there are accomplished female singers, such as the mockingbird, cardinal and Baltimore (northern) oriole. The pleasant sound of a bird’s song adds to the loveliness and interest in our world of nature.
Birds not only sing, they also make calls. Alarm calls are used to communicate with other birds of the same species, when danger is near. This alarm call is similar from species to species. If a cat, crow or other predator gets too close to a bird’s nest, the parent birds give an alarm call. This alarm call is not only answered by the birds of the same species but many other species of birds and some mammals. Often a hunter on stand will be discovered by a flock of blue jays, who will in turn alert the deer in the area.
A bird’s song is a rhythmic series of notes. Songs are usually given by the males as part of the courtship. Most people would agree that the thrushes, sparrows, mockingbirds, meadowlarks and wrens are among the finest songsters in Pennsylvania. However, there are some birds not classified as songbirds, such as the bobwhite quail and the mourning dove, which have pleasant songs.
Although birds generally sing during daylight hours, several species are noted for nighttime singing. Thrushes and whip-poor-wills often sing at dusk and the mockingbird will occasionally sing at night.
Most of the songbirds’ singing is done in the early morning, with singing diminishing by midday and then increasing in late afternoon. The midday slackening of song is often correlated with high heat. Also, birds either sing less or shift to muted songs when it is windy or humid. However, neither cloudy days nor a light rain seem to affect their singing.
Not all birds sing or make calls to communicate. Some birds send messages with their feathers. A grouse standing on a log makes a drumming sound by beating his wings, while a woodpecker taps out a message on hollow trees and even the rain gutters on a house.
Most male songbirds are good fathers and equally share duties with the female, of raising their young, while singing and doing their chores.
Well, I hope you enjoy the bird songs. In our area, this singing will end after the nesting season, a time when most songbirds will have a postnuptial molt and not want to call attraction to themselves.
Bill Bower is a retired Pennsylvania Game Commission Wildlife Officer. Read his blog and listen to his podcasts on the outdoors at www.onemaningreen.com.