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Trumpeter Swans Prepare for Migration October 27, 1997
"We're watching the young Trumpeters take flying lessons from their parents. They're running and bouncing over the water, flapping their wings, and staying in the air for only short distances. The young swans, called cygnets, must be able to fly away with their parents before the lakes freeze, and that's not so long from now," reports Daniel Gomez, Manager at Red Rocks Lakes National Wildlife Refuge. Trumpeter Swans, the largest and among the most majestic of all waterfowl, can weigh up to 30 pounds, so it's amazing that they can fly at all! Adults will grow to up to 5 feet in length, with wing spans of over 8 feet. Approximately 125 Trumpeter Swans live at Red Rocks Lakes National Wildlife Refuge and the Centennial Valley, located in southern Montana just north of Yellowstone National Park. Right now, as the cygnets prepare for their first migration, the Trumpeter Swans at Red Rocks Lakes are being joined by flocks of other Trumpeters which breed north of the refuge in Canada. These migrant Trumpeters will stop down at Red Rocks Lakes, as well as other surrounding lakes in the greater Yellowstone region, to feed and rest up throughout the month of November. As Montana's lakes begin to freeze in mid-November, whole families of Trumpeters will leave and travel together in close knit groups en route to wintering areas in Idaho.
Trumpeter Swans maintain strong family bonds. At three to four years of age, Trumpeters select a mate which they will keep for life. Pairs vigorously defend their territories by trumpeting loudly, running, and flapping their wings at intruders. Females will build nests and lay three to six eggs. If nests are defended and eggs incubated successfully, the baby cygnets will be born in mid-June. Adult Trumpeters Swans stay with their cygnets throughout the first several months of life. Reports from recoveries of banded and collared Trumpeters show entire family groups returning together to the same habitats where they spent the spring and summer months years before. Beauty Leads to Demise Trumpeters could once be found on lakes across Canada and the United States. However, their stark, white silhouettes provided the swans little camouflage. Hunters easily killed them for their meat and feathers. Thousands of robes made with the feathers of Trumpeters were shipped to Europe each year. By the early 1900's, Trumpeter Swans were nearly extinct. However, a small group of 68 Trumpeters was found in Centennial Valley. Red Rocks Lakes National Wildlife Refuge was created to provide protected habitat for these swans. Biologists at the refuge supplemented their natural food supply of aquatic plants with grain. Over the next couple of decades, the population of Trumpeter Swans gradually rebounded at Red Rocks Lakes. It became so strong that biologists captured and transported small groups of Trumpeters to other areas.
These efforts to reintroduce the Trumpeters to other areas have helped to distribute the population of Trumpeter Swans over more areas in the Rocky Mountain region. The overall Rocky Mountain population of Trumpeter Swans, which migrates through Montana, Wyoming, and Idaho, has rebounded from its dangerously low population size of 68 in the early 1900's to over 2,500. Including Trumpeters that breed in Alaska and the Midwest, there are now over 18,000 Trumpeters continent-wide. Changing Migration Patterns Historically, Trumpeter Swans migrated as far south as Colorado and Utah to feed during the winter months. Now the Red Rocks swans go only as far as Idaho.Why do you think Trumpeters are migrating shorter distances than they once did? The artificial feeding programs at Red Rock Lakes and other sites have helped to rebuild swan flocks. However, because humans have made food available in the winter at points north of the swans' traditional wintering grounds, the swans have actually changed their migration patterns. Migratory Trumpeters, which once journeyed and wintered further south, are now traveling only as far as Idaho. They have adapted to spending the winter in smaller areas, with a colder climate, and with a lower level of natural aquatic plants. While establishing populations of Trumpeters at many small sites has helped to bolster the overall population of Trumpeter Swans, some biologists worry that reintroduction programs, which break up family groups, disrupt the Trumpeters' social structure. Young swans need adults on which to bond and learn survival skills. So, when young are taken from their parents they may become disoriented and have a reduced chance for survival. Thus, while reintroduction programs and artificial feeding have helped swans rebuild their populations, these same programs may also be hurting Trumpeter Swans by changing their natural behavior.
We thank The Trumpeter Swan Society for providing photos for today's update! The Next Journey South Update Will be Posted on November 3, 1997.
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