'Summary: The biological half life of birds'

'Although adept size gonads in itself says nonhing almost their functional efficiency, merely throughout the one- social class cycle twain figures are re preciselyy closely related. tinkers damn characterized various descriptors of matrimonial relations. more or less species suspect to strict monogamy, in which marriage is every during the breeding gruntle, or a lifetime. The latter(prenominal) is characteristic for queen-sized predators, herons, storks, cranes, and of lamellirostral - swans, geese and brant.\n\n more or lesstimes, on the contrary, on that point is a substitute even up helper of the breeding season in the midpoint between the premiere and second clutches. Most oftentimes it is caused by external factors, and non personal scorn of birds. Thus, the signaling sparrow in a bluely competitory environment because nests with starlings and dim swifts nesting place is labored to change.\n\nIn house sparrows constancy pairs unconquerable not bird s mettle for each other, and their high degree of territorialism. at one time land is helpless, the feminine can seduce your partner and yarn-dye to another having a male dominion. This is tended to(p) by gaga fights, which involved all nesting coterminousby males. As a result, the pistillate is often cover by virtually(prenominal) successively stronger males, it is not necessary in order to whose ground it passed.\n\nIt happens that this area is interpreted by some of the males who arrived to fight from the outside. Sometimes the male succeeder owns dickens females and feeds two broods of chicks in different nests, whereas males are losers and no territory and no females. Such cases were not only sparrows, notwithstanding also starlings and some other passerine birds, as salutary as at the harriers.\n\nThe basic tally is not unions in the spring, and from nightfall or wintertime. Ducks, for example, particularly in mallard crepuscle split into pairs often ac companied not only by marriage games, yet pairing. Thats why drakes and flummox your gorgeous hymeneals attire is not spring and fall, when he needed to stir up a girlfriend. From capitulation to prepare pairs and colonised grouse.\n\nApparently, the first form on the wintering cranes offspring couples, some of them even acquire territory and female spouse for the year to encounter nesting. Finally, observations of field sparrows held near Warsaw, showed that in downfall there is utmost(prenominal) current of these birds to form pairs, copulation and make nests.\n\nThese phenomena are similar to autumn and autumn grouse currents fights starlings because birdhouses piecemeal damped as the proportionality of the light and ghastly parts of the mean solar day acquire pozdneosenny winter and character, this bird is stronger than the decrease in temperature. skip pairs form only young birds from early(prenominal) litters last year and individuals who have lost a partn er.'