Mountain-Prairie Region
Trumpeter Swan

What does a trumpeter swan look like and how can you tell the difference between on and a tundra swan?

Trumpeter swans are the largest native waterfowl species in North America. Tundra swans are nearly as large as trumpeters, and both have white feathers and black bills. Some, but not all, tundras have a yellow spot at the base of the bill near the eye. Trumpeters never have a yellow spot. These slight differences make accurate identification difficult in the wild. The two can be distinguished more readily by the differences in the sound of their calls.

How many trumpeter swans are there today?

Trumpeter swans occur in the wild only in North America. The most recent range-wide survey of trumpeters occurred in 2000, and counted nearly 24,000 birds. In contrast, the first year of the survey (1968) biologists counted only about 4,000 birds. From 1968 to 2000, trumpeters increased in abundance by about 6% per year. During the same time period, the Rocky Mountain Population of trumpeter swans, which primarily inhabits areas in and near the Rocky Mountains of the U.S. and Canada, increased from about 800 birds to more than 3,600 birds, at a rate of about 5% per year.

What is the tri-state flock and where is it located?

The birds in this flock inhabit areas of the Greater Yellowstone ecosystem, which includes Yellowstone National Park and adjacent area in Idaho, Montana, and Wyoming.

Why is the tri-state flock not considered a distinct population segment?

Historically, trumpeter swans ranged throughout much of Canada and the U.S. There is no evidence that the birds in the tri-state flock have been isolated from other groups of swans for a sufficient period of time for adaptations to occur and make this group a discrete and significant population. Current genetic information does not provide evidence that the birds in the tri-state area are genetically different from trumpeter swans in western Canada. Morphology and behaviors of the two groups also are similar. The tri-state flock has historic and sociological importance; but the flock is not significant from an evolutionary standpoint, and that must be a criterion used to deemed distinct population segment.

Are there a lot fewer birds in the tri-state area than there were historically?

Migratory birds generally were not monitored prior to the early 1900s. We don’t know how many birds inhabited the tri-state area before then. In the early 1930s only about 70 birds were counted in the area, compared to between 300 and 400 now. Many birds from the tri-state area also were relocated to other areas in attempts to establish new breeding flocks.

What are the major concerns about the status of tri-state birds?

Although the number of swans nesting in the tri-state region has increased since the early 1900s, their numbers are relatively low. These birds, together with swans from western Canada and relocated swans in Oregon and Nevada, are part of a larger group of trumpeter swans known as the Rocky Mountain Population, which numbers more than 3,600 birds. Most of these birds winter in the tri-state area, and some people fear that such a large concentration of birds could result in many birds dying due to inclement weather, insufficient natural foods, or disease. However, increased mortality that was believed to be caused by severe winter weather has only occurred once. For years biologists have tried to establish additional wintering areas to reduce the pressure on the tri-state area, but success has been limited.

Have trumpeter swans ever been listed as a threatened or endangered species?

No. In the early 1900s, only about 70 birds wee known to exist in and around Yellowstone National Park. The advent of aerial surveys helped biologists locate many more swans, particularly in remote areas of western Canada and Alaska. Although the species has never been listed in the United States, it was briefly listed as vulnerable in Canada. However, based upon a recent review of trumpeter swan status in Canada, the Canadian Federal government has decided they are not at risk of extinction.

Is there any indication that there is interaction between the swans from Canada and those in the tri-state area?

Yes. Although the two flocks do not nest near each other, they winter together primarily in the tri-state area. Limited marking studies have resulted in one observation of a mixed group (Canadian/tri-state) pairing. Additionally, two birds from the tri-state flock were sighted in Alberta, Canada, and two birds marked in Alberta were observed during summer in the tri-state area. These results suggest some reproductive intermingling of the two flocks may be occurring.

Is there a hunting season specifically designated for trumpeter swan?

No. Swan hunting seasons are designed to target tundra swans, which are much more numerous that trumpeter swans. As mentioned above, the two swan species are very difficult to differentiate in the field. To monitor and limit accidental deaths of trumpeter swans due to misidentification by hunters, limits of 10 trumpeter swans in Utah and five in Nevada are allowed during permit-only hunts in those states. All hunters that shoot a swan must take it to a check station to have it identified. If a limit is reached, all swan hunting is closed immediately in that state. This assures that the accidental harvest of trumpeter swans remains small.

How many trumpeters swans were killed in the Utah and Nevada hunts in the last few years?

Since 1994, only one trumpeter swan has been detected in the swan harvests in Nevada. In most years in Utah, between zero and three swans per year have been encountered at check stations, where hunters must take their swan to be identified. In one year (1997), seven trumpeters were shot in Utah. However, six of those birds were translocated from Idaho into the hunt area during the hunting season as part of a research program. The birds shot by hunters are from both the tri-state flock and the Canada flock, which has about 4,000 birds.

What is being done to improve the status of tri-state swans?

For several decades the U.S. Fish and Wildlife Service has joined with State agencies, Native American Tribes, non-governmental organizations, and private individuals to conduct many programs to improve the status of swans in the tri-state area. Although success has been limited, we have used tri-state birds to establish new breeding flocks of trumpeter swans in Nevada, Oregon, Wyoming, and South Dakota. Partners in the tri-state area and elsewhere have improved habitat for nesting and wintering swans. Management actions have resulted in a lower proportion of swans inhabiting core wintering areas where densities were very high. Although the number of birds in Montana has decreased, abundances in Idaho and Wyoming generally have increased over the last decade. Today, we have many more birds nesting in the tri-state area than in the 1930s. The Service remains committed to work with its partners on conservation efforts for trumpeter swans in the Rocky Mountain population, which includes birds in the tri-state area.

Last updated: September 26, 2008