Wyoming Wildlife - January 2024

A Majestic Return


Trumpeter swans can weigh up to 26 pounds and have wingspans that exceed 7 feet.


Trumpeter swans came back from the brink of extinction,


Elizabeth Boehm & Mark Gocke
1/1/2024 12:01:01 AM

In North America, a remarkable story of conservation and restoration unfolds — a story that revolves around the majestic trumpeter swan. They demand appreciation as the largest waterfowl species on the continent — weighing in at 26 pounds with wingspans exceeding 7 feet. These iconic birds, which have trumpet-like calls and a graceful presence, were once on the brink of extinction. However, they now serve as a shining example of species recovery— mostly.
 

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A newly-hatched brood of trumpeter swan cygnets huddle close to their parents on a private pond near Jackson. (Photo by Mark Gocke/WGFD)

HISTORY

Centuries ago, trumpeter swans were abundant across a wide portion of North America with numbers likely exceeding 100,000. They once nested across central Canada and into northern areas of the United States and migrated as far south as Texas and Louisiana in the winter seeking forage in unfrozen habitat. Beginning in the 1600s through the early 1900s, habitat loss, unregulated hunting and their naturally low reproduction rates took a heavy toll on the population. People often used their feathers as writing quills, to adorn women’s hats and as stuffing for quilts and mattresses. Beavers also were nearly wiped out at the time, eliminating much of the crucial habitat swans relied on. By the early 20th century, the extinction of trumpeter swans was thought to be only a few years away.

With intervention, extinction was narrowly missed. In 1918, Congress passed the Migratory Bird Treaty Act, safeguarding many bird species from harm by people. At this point, it was estimated only 69 trumpeter swans remained in the lower 48. The only known population was in the Greater Yellowstone Area.

With federal protection in place, in 1932 President Franklin Roosevelt allowed the purchase and conservation of the 40,000-acre Red Rocks Migratory Bird Refuge in Montana north of Yellowstone National Park and in the core range of these surviving birds. The birds finally began to rebound, and their numbers grew in just five years.

Still, conservationists and wildlife agencies 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.

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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)

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.

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Growth in the resident GYF population. 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 as we switched to develop plans and obtain funding for construction of new ponds on private ranches. I worked with wonderful landowners who embraced swan conservation and understood the importance of wetlands for wildlife. Continued management and restoration of wetland habitat will be needed in the future to maintain a robust nesting population in arid Wyoming.”

Concern remains over the low productivity of nest sites and fewer nesting pairs in the Snake River core area in northwest Wyoming. Forage has been hypothesized as a limiting factor for resident swans in the Snake River core area as it seems migratory swans in the RMP may reduce available spring forage. Most migrant swans head north by late March or early April, leaving resident breeding swans to forage on remaining aquatic vegetation until additional wetlands thaw and open. In cold, late springs when the thaw is delayed, available vegetation is in short supply during the pre-nesting period, resulting in a reduced number of eggs laid in nests.

Inside Yellowstone National Park, trumpeter swans peaked at 72 in 1961 but then declined. Releases of birds continue in the park, but the productivity of nesting pairs remains low. Much of this may be due to
long-term drought, less favorable weather conditions and more marginal nesting habitat.

FUTURE

Wyoming trumpeter swan numbers are not meeting objectives for the number of breeding birds managers would like on the landscape. Wyoming averages only 14 successful pairs that hatch 2.2 cygnets a year.

While growing exponentially for a number of years, the population of Green River area birds has leveled off in recent years, which suggests the population may have reached the suitable nesting capacity in the wetland areas and more habitat may be needed to see trumpeter swan populations increase. It is unknown at this time if there are birds moving out from the Green River area and into other suitable habitats.

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Susan Patla, former Wyoming Game and Fish Department nongame biologist, fits a neckband on an adult trumpeter swan to map its travels before being released into the wild near Jackson. (Photo by Mark Gocke/WGFD)

“As a place that has always had trumpeters even when they were at their lowest, we want to make sure these impressive birds stick around long term, and our flocks are resilient enough to weather changes to the climate and landscape,” said Noelle Smith, Game and Fish migratory game bird and wetland biologist.

Reintroductions of the birds in the Wind River Indian Reservation have been successful in recent years, and Game and Fish continues to explore new wetlands for possible flock expansion. One of those is in the Big Sandy area. Big Sandy lies to the south of the Green River Basin and includes the Big Sandy River, Big Sandy Reservoir and associated wetlands as well foothill wetlands in the Wind River Mountains.

“It appears that the Green River population has been using the area below Fontenelle Dam on the Green River for wintering. The Big Sandy project is an effort to provide other wintering and potential nesting areas and bolster swan numbers in southern Wyoming,”said Bill Long, Wyoming Wetland Society founder and program director.

An upcoming project will release five to 10 cygnets at these identified wet areas each year for 10 years. The cygnets will be captive-reared at the Wyoming Wetland Society’s Jackson-area facility and released in early July each year.

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Patla and Drew Reed with the Wyoming Wetland's Society release an adult and its grown cygnet at the South Park Wildlife Habitat Management Area south of Jackson. (Photo by Mark Gocke/WGFD)

All the reintroduction programs require monitoring to assess the success of the initiatives and gain insights into the swans' behavior, movement patterns, breeding habits and nest productivity. Scientists and wildlife
biologists use banding techniques, satellite tracking and other innovative methods to gather data.

Compared to the 1990s the status of the resident Wyoming trumpeter swan population has dramatically improved. The number and distribution of swans has increased since then as has the amount of important wetland habitat in the state. The number rose to a peak of 236 adults and 67 cygnets in 2016. The number of birds has dropped to 134 adults and 54 cygnets in 2023. Biologists believe this drop means the population has leveled out to a sustainable number with the amount of current suitable habitat. These efforts are seen as successful in Wyoming and across North America and are a testament to the collaboration and dedication of numerous organizations, agencies and passionate individuals. While certain risks remain for the Greater Yellowstone Flock, the commitment by many to restoring the ecological balance and preserving part of our natural heritage has already yielded remarkable results.

Rene Schell is the information and education specialist in the Lander Region.



 

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