In April many Yukoners celebrate the return of Trumpeter Swans to the North by heading out to M'Clintock Bay on Marsh Lake. For all we humans know, the swans feeding there might be celebrating too. Many of them have spent their winter eating potatoes on farmers' fields down South, where life can be less than tranquil for them.

The birds have been forced onto agricultural land as much of their former wetland habitat has been drained and diked. About 2,000 trumpeter swans, around ten percent of the world's population, winter in the Comox Valley on the east side of Vancouver Island.

This sheltered valley is a productive area for both farms and swans. But farmers have not always welcomed the swans with open arms because these large birds can wreak havoc on their land.

In flooded fields, the swans create bathtub-size craters while searching for unharvested potatoes and carrots. They overgraze perennial grass, pulling it out by its roots, and compact the soil with their large webbed feet. Kathleen Fry, a Ducks Unlimited biologist, says that after swans have foraged on a field "it looks as though a series of lawnmowers has moved through the area."

The farmers' rule of thumb is that 10 swans consume as much forage as one cow. 500 swans can lay waste to a dairy pasture, so not surprisingly, some farmers think of swans as pests.

Fry is based in Surrey, BC, and works with the Comox Valley Waterfowl Management Project, also known as "Swans on the Lawn". The project attempts to help swans and farmers co-exist by limiting the damage that swans inflict on farmers' fields while ensuring that the birds get enough to eat. Both Ducks Unlimited and the Canadian Wildlife Service support the project, which started in 1991.

Farmers are paid $25 per acre for planting winter cover crops that will lure swans away from more valuable perennial grasses. These crops also help protect the soil during the rainy winter months. Each winter about 200 hectares are planted in cover crops where the swans can feed undisturbed.

Scare tactics are used to keep the swans off of valuable grass fields, and biologists have been learning through trial and error what a swan will find scary. For example, swans stayed away from fields in which large blue plastic barrels were planted on sticks, but they ignored silver metal barrels. White barrels seemed to actually attract the birds.

More exotic techniques have also been tried, but the normal method is to use a four-footed swan chaser. When a farmer calls in because a flock of swans is feeding in his pasture, the project coordinator lets his dog loose in the field.

The program is considered to be a success story. But even farmers who support the program wonder how many swans could eventually end up wintering on their fields. Every year more and more swans return to the area, and some people wonder just how high the numbers could go.

Fry says that she always tries to remind farmers that it only seems like there are a lot of swans around these days because the species is still on the rebound. Overhunting drove trumpeter swans to the verge of extinction in the early part of this century.

Since then, conservation efforts have made trumpeter swans an endangered species success story. For the last 40 years or so their numbers have about doubled every decade. It's estimated that now there are about 17,000 swans along the Pacific Flyway.

Fry does not want to predict what the future could hold for trumpeter swans. "It's impossible to say whether the number of swans will continue to increase. The wintering grounds could well be the limiting factor," she says.

Wetlands and natural areas have continued to disappear ever since 1963 when the swans began reappearing in the valley. "Comox Harbour has been dredged and rip-rapped. The marsh zone isn't there. They can't root around for rhizomes in the harbour, so they eat spuds," explains Fry.

Swan supporters continually work to educate people about the close ties between agriculture and swans in the Comox Valley. "Think like a swan, eat locally grown food" is the motto of Comox's Trumpeter Swan Week, held in early February.

But population growth in the area continues to threaten the birds, as there is more pressure to turn farmland into new subdivisions. The project is trying to ensure that key agricultural areas are kept intact. In 1998, Ducks Unlimited helped buy Farquharson Farms, which lies next to a busy road in the Courtenay-Comox area. A mall with a Canadian Superstore borders the fields.

Some swans gather on more remote dairy farms, but large flocks also feed in central areas such as Farquharson Farms. Fry says it's fortunate that the birds are less territorial and edgy in winter than they are in spring.

On their wintering grounds swans are still skittish around people, but more inclined to co-exist peacefully in large flocks. In the spring, swans break off into smaller groups, and the birds are more aggressive with each other.

When the swans arrive in the southern Yukon in the spring, they are only partway through their long migration to Alaska and the northern Yukon where they nest and breed. Here they need the chance to feed on the abundant aquatic vegetation in places like M'Clintock Bay, and to take a well-deserved rest.

For more information on Trumpeter Swans in the Yukon, call the Canadian Wildlife Service at 667-3929 or Ducks Unlimited at 668-3825.