Geese Steal Osprey Nests, Forcing The Birds To Risk Electrocution

Canada geese might be thought of as ground nesters, but they’ll take over old eagles’ nests up in trees or barge into elevated platforms meant for ospreys.

And when they hog the ospreys’ platforms, the ospreys are forced to try building nests on power-line poles, where they risk electrocution.

Some Canada geese nest on the ground, or in old wheelbarrows. Others with more of a taste for heights will build nests on outcroppings along cliff faces and hatch their young, called goslings, up there.

In short, the big, ill-tempered honkers set up nests pretty much anywhere they feel like it. Because after all, who is going to tell them different?

When a goose nest is someplace way up high, and the goslings are old enough to walk and swim, but not ready to fly, they’ve got one choice.

They jump out of the nest and hope for the best.

It usually works out for the goslings, biologist Bryan Bedrosian told Cowboy State Daily.  

“They’re fluffy enough to where they just bounce when they hit the ground and not break a wing or anything like that,” said Bedrosian, the conservation director for the Teton Raptor Center.

The geese finish raising their goslings on the ground and water, he added.

Honkers Are Opportunists

As mean as Canada geese are, there’s no evidence that they actually chase big raptors, such as eagles and osprey, out of their nests, said Bedrosian and Courtney Rudd, Wyoming Game and Fish migratory game bird and wetland biologist.

Rather, geese might sometimes move into vacated golden or bald eagle nests in trees or other high perches, Rudd said.

She recalled seeing a pair of Canada geese nesting in an old eagles’ nest in the Jackson area.

Bedrosian said he was a bit taken aback the first time he saw honkers way up high in an old eagles’ nest.

As he approached, expecting to see an eagle staring down at him, “I thought, ‘I swear that’s a goose face looking down at me,’” he said.

“It really throws you for a loop the first time you see it,” he added.

Geese are “generalists and opportunists” when it comes to nesting areas, so long as the nesting sites are reasonably near water, Rudd said.

Breeding and nesting season for geese in Wyoming can vary, depending upon the weather and other factors.

In general terms, it starts sometime between mid-February and mid-March, Rudd said.

Timing Hunting Seasons Right

Because ducks and geese migrate across state lines, the U.S. Fish and Wildlife Service (USFWS) also has jurisdiction over waterfowl hunting seasons in Wyoming and other states.

In addition to a Wyoming gamebird/small game hunting license, waterfowl hunters must have a federal migratory bird hunting and conservation stamp.

Hunting seasons are set to end before they interfere with Canada goose breeding and nesting, Rudd said.

“In general, the USFWS waterfowl frameworks for dark goose end dates roughly correlate to initiation of pre-breeding behaviors such as migration and pair formation. These end dates can vary by flyway, but don't typically shift significantly from year to year,” she said.

Saving Osprey From Electrocution

Because Canada geese in Wyoming sometimes start breeding and nesting so early, they can beat osprey to the punch in claiming prime nesting sites, Bedrosian said.

“They pick the nest first and once they’ve established a nest, they are super-defensive,” he said.

Osprey make the spring migration back into Wyoming from Mexico or other points far to the south. If they find geese already occupying nesting platforms that conservationists have built for them, the osprey move on, rather than risking a brawl with the geese.

“The risk for the osprey isn’t so much that they lose that nest, it’s where they chose to go next,” Bedrosian said.

“Almost always, they’re going to start using power line poles. That creates the risk of electrocution for the birds, and it can also cause power outages,” he said.

To discourage geese from stealing the osprey nesting platforms, conservationists came up with a simple, ingenious solution.

They designed the platforms to tilt at a steep angle early in the season, held in place by a cable.

That keeps the geese from using them because “the angle is steep enough the eggs will just roll off,” he said.

That forces the geese to seek other nesting sites.

Once raptor researchers are confident that the geese have moved on, they adjust the cables to level the platform back out, making it an inviting destination for the osprey to nest and hatch their young, he said.

Mark Heinz can be reached at mark@cowboystatedaily.com.