in Our Backyards
ESTABLISHING & DEFENDING TERRITORIES
Male birds of some species, such as American Robins, claim areas that may include one or more entire backyards. While nesting takes place, the males "defend" their territory against other males of their species; they sing to let other males know of their presence, and they physically confront, perhaps even fight (usually bloodlessly) other males attempting to cross into their territories. Other bird species, such as House Sparrows, may have very small territories that include only a nest and two or three feet of space around the nest.
Courtship is that period starting when males and females first meet, until the time they mate. Behavior during courtship varies tremendously from species to species. Brightly colored male tanagers and orioles parade themselves before the females. Buntings flutter over fields, loudly singing. Woodpeckers drum with their bills on dead limbs and aluminum house-gutters. Male Cardinals ritually feed their potential mates, and male hummingbirds perform complex flying patterns as the female watches. In each case the basic idea is for the male to impress the female with his vigor and sexual enthusiasm.
A few species do not build nests. Oystercatchers, for instance, lay their eggs in shallow, unlined depressions dug with their feet in sandy beaches. Nighthawks may nest on bare, flat roofs of buildings. When birds do build nests, the nests vary from the hummingbirds' elegant little creations held together with cobwebs, to mud nests built by some swallows, to messy assemblages of sticks, straws, and other items, made by House Sparrows.
Each species has its preferred nest-building materials, but some species can show surprising flexibility. A Warbling Vireo's nest was built almost entirely of Kleenex; in Minnesota a Brown Thrasher's nest was found with a five-dollar bill woven into the cup. In Texas, a White-necked raven built a nest completely of barbed wire. A pair of Canyon Wrens in California built a nest containing a total of 1,791 countable items -- all office supplies such as thumbtacks and rubber bands.
For a more detailed look at nest building, visit our bird-nest page.
Family raising begins with egg-laying and continues through incubation, hatching, the time during which nestlings remain in their nest needing to be fed, and ends when the birds have become fledglings outside the nest, and no longer need their parents' help.
During this fast-paced period of development, birds can be the most conspicuous and interesting. If you find a nest with young birds in it, don't disturb it, else the parents may abandon it. If you want to protect a nest in your backyard, the best thing you can do is to keep the cat inside; nothing kills more backyard nestlings and fledglings than house cats.
During the young birds' fledgling stage, when they can almost but not quite fend for themselves, watch for the time when the parents are losing interest in constantly feeding them, yet the fledglings obviously prefer begging and being fed, to foraging for their own meals! Just try to avoid anthropomorphically interpreting moments of "frayed nerves," "temper tantrums," and "parents feeling guilty and making up"!
Birds of the same species often flock together. After the nesting season, for instance, American Robins undergo complete personality changes. No longer do they defend their territories and clash with their neighbors; now they flock together feeding and migrate southward together. In late summer, flocks of young House Sparrows roost together chirping and calling. During this highly social period you can see many forms of communication, including a number of "displays."
If you happen to live in Eastern North America, you might have a lot of fun participating in Operation Rubythroat, a "cross-disciplinary international initiative in which students, teachers, and others collaborate to study behavior and distribution of the Ruby-throated Hummingbird (Archilochus colubris).