More info for the term: tundra
Age at first breeding - Tundra swans first breed when they are 2 or
3 years old. They form lifelong monogamous pairs [10].
Nesting - Tundra swans start nesting in late May to late June depending
on location and weather [2,10].
Clutch size and incubation - Tundra swans generally lay a clutch of four
or five eggs [6,10]. The incubation period is 30 to 32 days [10].
Cygnet development and fledging - Tundra swan cygnets are generally able
to fly within 9 to 10 weeks. The family remains together during the
fall migration, through winter, and during spring migration [10].
Molt - On the Yukon Delta, adult tundra swans molt between July and
August and regain flight within 35 to 40 days. Nonbreeders, which
remain in flocks of 3 to 15 during the breeding season, regain flight in
late August and begin to congregate in sizable flocks [2].
Fall migration - Tundra swans migrate in family units, with several
families and probably some nonbreeding birds combining in a single flock
[2]. In the West, tundra swans leave major breeding grounds in Alaska
in late September and early October. Marshes adjoining the eastern
shore of Great Salt Lake begin to receive tundra swans in mid-October.
Tundra swans begin arriving at the Malheur National Wildlife Refuge in
Oregon from mid- to late November and remain abundant well into
December. In the Klamath basins of Oregon and California, wintering
tundra swans do not arrive in substantial numbers until late November
and early December. On winter grounds adjacent to San Francisco Bay,
the swans are not present in great numbers until early December [2].
The eastern contingent of tundra swans passes across Minnesota,
Wisconsin, and Michigan, largely during November 5 to 15. Tundra swans
on Chesapeake Bay slowly increase in numbers through December and reach
a peak in January [2].
Spring migration - Tundra swans begin leaving their winter habitat after
the first spring thaw [2]. Tundra swans from Chesapeake Bay cross
Pennsylvania to Lake Erie from the first week in March into early April.
Tundra swans leave their central California winter grounds in
mid-February, and within 3 weeks almost all have departed. By early
April most have migrated north to Alaska and Canada. The first swans
generally reach their breeding grounds on the Yukon Delta in late April
and almost all arrive by mid-May. The western population of tundra
swans migrate earlier and more swiftly than its eastern counterpart [2].