Deadly Decoration

Deadly Decoration

When ospreys line their nests with baling twine, the results can be grim. By Alyse Backus.

This story is featured in Montana Outdoors July-August 2016 issue

If you’ve ever seen an osprey nest perched atop a telephone pole, you’ve likely also seen orange strings dangling from the twigs and sticks. That’s baling twine. Ospreys gather it, along with other soft materials such as grass and moss, to line their nests. But unlike natural materials, baling twine does not decompose. And the polypropylene string is so strong that when ospreys become entangled they can’t break free.

Erick Greene, a biology professor at the University of Montana who monitors ospreys in several northwestern states, says that no other raptor favors baling twine as much as ospreys do. “They seem to have a really weird addiction to it, and we don’t know why,” he says. “I’ve seen a bald eagle nest right next to a red-tailed hawk nest right next to an osprey nest, and the osprey nest is the only one with baling twine.”

Greene can only speculate why ospreys seek out the orange string. “In other ecosystems, ospreys use brightly colored lichens to line their nests, so maybe they’re attracted to baling twine because its color is similar to lichens,” he says.

Ospreys gather remarkable amounts of the bright twine, which is used to tie up hay bales fed to cattle or employed for erosion control in road construction. In 2010, volunteers with the Raptor View Research Institute in Missoula found a 20-year-old nest blown down in a storm containing more than 1,000 feet of baling twine. Greene says one blown-down nest he dissected contained nearly a half mile of discarded twine.

When ospreys pick twine up from fields or farm yards, the material tangles easily in the birds’ sharp, deeply curved talons. Birds caught in twine can starve to death, strangle, or suffer debilitating injuries to their feet and wings. Based on a study done in Alberta, Greene estimates that between 5 to 10 percent of osprey chicks and adults in Montana die from baling twine entanglement.

In addition, elk, deer, and other wildlife can become ensnared in loose twine, and curious cattle have been known to eat the material and die after it accumulates in the animals’ rumen.

Kate Davis, executive director at the Raptors of the Rockies conservation and rehabilitation center in the Bitterroot Valley, has rescued several entangled ospreys. One had twine tightly wound around a foot that caused a deformity as the bird grew. “We had to euthanize it because there was no way it could survive with just one functional leg,” she says.

Without human intervention, an entangled osprey’s chances of surviving are slim. “Getting wrapped up in baling twine or hanging upside down from the nest can be a death sentence,” says Davis.

Osprey advocates across Montana are raising awareness of the twine problem. The University of Montana and the Missoula-based Raptor View Research Institute have produced a brochure on ospreys and baling twine and distributed it to landowners and school groups.

Sometimes a tangled osprey gets lucky when an angler or bird watcher notices it hanging from a nest and makes a life-saving call. Greene says linemen from the Missoula Electric Cooperative and NorthWestern Energy use their bucket trucks to retrieve tangled birds and trim loose baling twine from osprey nests to prevent future entanglements. “We have the necessary permits from Montana Fish, Wildlife & Parks and the U.S. Fish & Wildlife Service to do rescues and approach osprey nests. But we don’t have the authority or equipment to approach live power lines,” says Greene, who founded the Montana Osprey Project to study osprey ecology in the upper Clark Fork River watershed. “We have a great relationship with the electric companies when it comes to rescues and trimming baling twine from nests.” He adds that NorthWestern Energy recently included information on ospreys and baling twine with customers’ energy bills.

Greene has begun talking to other utility companies to see if he can create partnerships similar to those in Missoula. “Ospreys like to nest near or on power poles, and, if tangled, the birds can cause shorts in circuits that can lead to fires or other damage,” he says. “So the cooperation is beneficial to both parties.”

The most obvious way to save ospreys from baling twine is to eliminate the source. Some Audubon chapter members pick up baling twine along roadsides and encourage landowners to put loose twine in lidded garbage cans or 45-gallon drums where ospreys can’t reach it. “We’re trying to talk with as many people as possible about the dangers of baling twine to ospreys,” says Lisa Bessasparis, a volunteer with the Yellowstone Valley Audubon Society and leader of the group’s Baling Twine Committee. “Some people just don’t realize that when they toss it on the ground or into the back of a truck it can end up in an osprey nest.”

Greene works with 4-H clubs and Future Farmers of America members who volunteer to clean up twine on ranches. “It’s something tangible kids can do, and they often contact their neighbors or relatives to see if they can do a cleanup,” he says.

One challenge is disposing of the excess material. When burned, the petrochemical-based twine emits toxic fumes. Greene says a few communities in Idaho have begun working with ranchers on a baling twine recycling program. Conservationists in the Bitterroot Valley and elsewhere in Montana are trying to figure out if a recycling effort could work here.

Greene says most ranchers pick up excess twine, but sometimes the material blows loose in windy weather. “It only takes one or two messy fields to create a problem,” he says. “Ospreys love the stuff, and they will make long trips to get it. Our goal is to make sure they can’t find any loose twine anywhere in Montana.”

If you see an osprey tangled in baling twine, call your local FWP office. To learn more about Project Osprey, visit projectosprey@mso.umt.edu.Bear bullet

 

­­Alyse Backus is a writer in Billings.

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