During the month of March, I made many diary entries about birds that I had seen returning from their migrations.

In the morning when I step outside, I hear the singing of robins, cardinals, doves, crows and more, and all are singing to attract a mate.

Have you ever wondered why species of birds do not interbreed in the wild? Generally, there’s enough of the same species to allow for the same species breeding. However, two birds of similar but different species, in captivity, where there is only one option to satisfy their mating urge, could mate.

If there is an offspring of this mating, it will be a hybrid and more than likely sterile. For this interbreeding to occur, it must be a very similar species because birds — unlike dogs — cannot interbreed with just any species of bird.

When Mary Alice and I go for our walks, many cars pass by, with the occupants either waving or beeping their horns because they recognize us. The same happens when making a telephone call and the person answering identifies the caller by his or her voice.

Birds also recognize their own species by the bright colors of the males, their calls, songs and behavior. Even though calls of the same species sound alike to us, birds can tell the difference. In studies done, it has been found that birds are able to recognize their mates in flight. Mated pintail ducks have been known to identify each other up to 300 yards away, while bobwhite quail can distinguish each other in the covey.

A mated pair of songbirds protect their territory, and often, the female will chase another male away because she recognized that this male was not her mate. On the other hand, studies have shown that doves do not know the sex of a strange bird until they are at close quarters, and ruffed grouse do not have any sex recognition at all.

Some birds mate for life (Canada goose), while some remain together through at least one nesting season. Birds such as wrens and swallows will pair with the same mate the following year and perhaps even for three years. The pairing of hummingbirds can be so brief that it is called a promiscuous relationship. After the female builds a nest, she mates with the first male hummingbird she meets, lays her eggs and raises the young without any help from the male.

The male will then seek out another female and mate again. The ruffed grouse is another example of a promiscuous relationship.

When the female mates more than one male it is known as polyandry. Among birds, this is quite common in pheasants, turkeys, red-winged blackbirds and bobolinks and other songbirds. When a male mates with several females it is called polygynya. Usually, the females lay and incubate their eggs, in separate nests, without any help from the male.

Polyandry is relatively uncommon. It is known among birds in which the role of the sexes in the family has been reversed. The female, which is larger and usually has brighter plumage, will solicit the male and defend a common territory, the male, which is smaller and drabber, will build the nest.

The female then lays the eggs, and the male does all the incubation and most of the care for the young after hatching. The female belted kingfisher is more colorful than the male, and the two appear to have switched roles.

Inbreeding, within a family group, is rare among birds in the wild because of the dispersal of the young after the nesting season is over and the intolerance of the adults towards their young when grown. Even though these young birds return to the home territory of their parents, during the following spring, there appears to be no interbreeding.

Inbreeding is so rare that it has only been documented three times: in a downy woodpecker family, a brother and sister mated; a barn swallow father and daughter mated; and a tree swallow mother and a son mated.

While the songbirds are singing and exhibiting their mating flights to attract mates, we humans have a front row seat to watch and listen.

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.