Waterfowl
Reports
Alaska
Trumpeter Swan Survey
Trumpeter
Swans (Cygnus buccinator) summer in Alaska in the forested wetlands of the interior
and along the coastal plain from Cook Inlet south to the Chilkat Valley. They
historically wintered in estuaries and fresh water lakes and streams from Cook
Inlet to the Columbia River in Washington and perhaps as far south as California,
but primarily in British Columbia (Bellrose 1976). In recent years a growing proportion
of them are spending a major part of their winter cycle foraging in farm fields
from southern British Columbia to California.
Records of Trumpeters in Alaska
go back to at least the 1860's (Banko 1960, Dall and Banister 1869), but a breeding
population was not described until 1954 (Monson 1956). Shortly after this, additional
nesting Trumpeters were identified on the Kenai Peninsula, the Gulkana area, and
the Minto area near Fairbanks (Hansen et al. 1971).
Early attempts to census
Trumpeters from the air found 1,124 in 1959 and were described by Hansen et al.
(1971). Poor quality maps precluded accurate plotting of swan sightings, thus
that survey can not be directly compared with the censuses starting in 1968. By
1968 nearly the entire Trumpeter nesting habitat in Alaska was covered by U.S.
Geological Survey (USGS) l:63,360 (1 inch = 1 mile, 25 mm = 1.6 km) scale topographic
maps with contour intervals of 100 feet (30.5 m). The 1968 Trumpeter Swan census
included all known nesting habitats except the Kuskokwim and the Koyukuk units
and every swan sighting was marked on a 1:63,360 scale map. Statewide aerial censuses
in 1975, 1980, 1985, 1990 and 1995 included all summering habitat, followed the
same procedures and thus are all directly comparable. The total number of trumpeter
swans counted in 1995 was 15,823.
Last Updated: September 15, 2008
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