38 MATING AND NESTING HABITS 



MATING AND NESTING HABITS 



MATING HABITS 



Swans and Geese are presumed to mate for life. In some cases, if 

 either partner is killed, the survivor is believed never to pair again. 

 Ducks, on the other hand, probably seek new mates each season. 



In the case of those species that mate each year, courtship takes 

 place in late winter and during the spring. There is much competition 

 among males for the possession of a mate, and the courtship displays con- 

 sist of many interesting and curious antics. In some species, mating takes 

 place before migration to their summer range, and in others mating is 

 deferred until the journey is accomplished. 



Upon arrival on their breeding grounds the birds lose little time in 

 starting the search for a suitable nesting site and in building their nests. 

 Eggs are usually deposited on consecutive days until the clutch is com- 

 plete. Incubation, on the average, takes about 28 days in the case of the 

 Ducks, and somewhat longer with the Swans and Geese. Should the eggs 

 be destroyed before the set is complete, it is usual that another set will 

 be laid. Only one brood of young is raised each season, except perhaps 

 occasionally in the case of the Ruddy Duck. The young birds are fully 

 grown and strong on the wing before time for the autumn migration 

 arrives. 



The males of the Swans and Geese, while not assisting in the process 

 of incubation, remain close by and invariably assist in the care of the 

 young. In the case of most Ducks, as soon as incubation is well started 

 the males withdraw into flocks by themselves and proceed to moult into 

 the eclipse plumage, taking no part in family cares. 



The male Ruddy Duck and the male Red-breasted Merganser usually 

 assist in rearing the young, as does occasionally the male Cinnamon Teal. 



The Swans do not, as a rule, breed before their fourth year; Geese 

 usually breed in their third year. All River and Pond Ducks breed be- 

 fore they are a year old. Most Diving Ducks likewise breed in the spring 

 following their hatching, the exceptions being Golden-eyes, Buffle-head, 

 Old-squaw, and Harlequins, which do not breed until two years old. 

 The Eiders and Scoters do not breed until their second or third year. 



NESTING HABITS 



The Swans always nest on the ground, building bulky structures in 

 close proximity to water. 



The Geese generally nest on the ground, but occasionally some 

 species will occupy the disused nests of hawks or other large birds situated 

 in the forks of trees. The Barnacle Goose nests in hilly regions and the 

 nests are usually placed on faces of inaccessible cliffs and precipices. 



The River and Pond Ducks usually nest on the ground, with the ex- 

 ception of the Wood Duck, which invariably nests in hollow trees or 

 stumps. Occasionally Mallards and Black Ducks will occupy abandoned 

 hawks' nests situated in tree crotches, and at times even use unoccupied 



