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knew they had much work to do to restore the
population across more of their historic range.
It would be an uphill endeavor as trumpeter
swans have specific needs. Conservationists
had to solve key puzzles to restore the birds
to areas where they were absent. Migration
traditions had been lost in many areas, and
trumpeter swans did not always explore new
locations without an existing swan presence.
They have exacting tastes and habits. They
require a shallow wetland with an irregular
shoreline, abundant and elevated nest sites,
high volume and diversity of food like submerged
aquatic vegetation and emergent
plants, a low level of human disturbance
and a long, unobstructed runway for takeoff.
RECOVERY
Early reintroduction efforts had mixed success.
Captive-reared birds had limited genetic
diversity and had to learn about migration
and environmental conditions without older,
established birds. However, the perseverance
of conservationists and a better understanding
of the needs of trumpeter swans paved the
way for more successful reintroduction efforts
in later years.
Today, the swans' breeding range is more
fragmented, and separate populations are now
recognized: Pacific Coast, Rocky Mountain
and Interior. The Greater Yellowstone Flock
is the U.S. segment of the Rocky Mountain
Population and spans Idaho, Montana and
Wyoming. While most trumpeter swan populations
in North America are thriving with
approximately 63,000 birds, the U.S. segment
of the RMP still faces threats and has been
slower to recover. There are about 923 birds in
the RMP, and 185 of those are in Wyoming.
Since the late 1980s, the Wyoming Game
and Fish Department has actively monitored
and managed trumpeter swans in the Greater
Yellowstone Flock in partnership with the
U.S. Fish and Wildlife Service, Pacific Flyway
Council and the states of Idaho and Montana.
Recovery efforts in the GYF have focused on
expanding summer and winter distribution
through releases of captive-reared cygnets
and habitat improvement projects. All of
the swans that previously migrated into the
southern U.S. were long ago wiped out by
humans, a demonstration of how migration
memory loss can have lasting consequences
for a species. To expand, the swan's range now
requires humans to introduce the birds into
new habitats, called translocation.
Growth in the resident GYF population
A freshly-hatched trumpeter swan cygnet watches as its sibling works its way out of its egg while in an incubator at
the Wyoming Wetlands Society's captive-rearing facility in Jackson. (Photo by Mark Gocke/WGFD)
can be attributed to range expansion efforts in
the Salt River and Green River basins. From
1992-2004 the Upper Green River Expansion
Area Project expanded and improved wetlands
and translocated more than 100 cygnets. To
accommodate the growing number of swans
in the Green River Basin, Game and Fish
collaborated with various organizations, landowners
and dedicated individuals to initiate a
wetland habitat program focused on assisting
landowners in developing shallow-water, wetland
ponds that provide additional summer
habitat and forage. The majority of Wyoming's
breeding swans are now in this area.
" Working on the Green River trumpeter
swan range expansion project was one of the
highlights of my career at the department, "
said retired Game and Fish Nongame Biologist
Susan Patla. " We released swans for
10 years before the number of nesting pairs
started to increase steadily. The most productive
swan nesting habitat in the Green River
region is found on managed wetlands such as
those at Seedskadee National Wildlife Refuge.
After we stopped releasing swans in 2002,
it was an exciting and nerve-wracking time
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January 2024

Table of Contents for the Digital Edition of January 2024