Birds get entangled in plastic string used for nests
By Ann McCreary
Pat Leigh of Winthrop was practicing digital photography recently, taking pictures of ospreys in a large nest high in a snag off of Twin Lakes Road.
She noticed brightly colored material among the sticks that made the nest, but it wasn’t until she got home and studied her photos on her computer screen that she realized what she was looking at.
“I said, ‘Oh my gosh, this is a dead osprey!’”
The osprey was hanging upside down below the nest, tangled in blue and orange string. The bird appeared to have been there for some time.
What Leigh captured in her photo is, unfortunately, not an uncommon fate for ospreys in the Northwest, according to bird experts.
While ospreys build their nests primarily of sticks, moss and other natural materials, the birds also have an attraction — which sometimes proves fatal — for brightly colored baling twine, used to tie up hay bales.
In places like the Methow Valley, with lots of hay fields and livestock, discarded baling twine is abundant.
“They target baling twine. They go out of their way to find it,” said Kate Davis, founder of Raptors of the Rockies, an educational organization based in eastern Montana.
“It’s really a common problem now,” said Bud Anderson, a biologist with the Falcon Research Group in Bow, Washington. In western Washington, fishing line collected by ospreys poses a greater risk to the birds, he said.
“Over there where you are, and further east where all the hay is baled, it [baling twine] is really a problem.”
The problem is that the plastic twine can become frayed and shredded, and the ospreys can become entangled in it — particularly their legs and claws, Davis said. The birds can die by strangulation, or starve because they can’t fly off to find food.
Chicks in the nest can also become caught in the twine.
“What happens is the young often get tangled up in the nest and their limbs are deformed, and they are doomed,” Davis said. “It’s tragic.”
Ospreys like to collect an assortment of objects to adorn their nests, including materials such as grasses, moss and lichens and manmade objects such as articles of clothing and paper products. Davis said she has seen a nest with a bathing suit top woven among the branches and sticks.
“Ospreys are very decorative when it comes to nest building. They love to pick up junk. Nest building is a courtship thing. They keep adding to it,” Davis said.
“One of the things I see more often than not is some kind of stringy stuff hanging down from the nest,” said Kent Woodruff, a wildlife biologist with Washington Department of Fish and Wildlife (WDFW) in the Methow Valley. Often that “stringy stuff” includes baling twine.
“Baling twine is a big, beautiful, easy-to-spot decorative item” for osprey, but humans can reduce the risk it poses to the raptors, Davis said.
“It’s so easily remedied. Just pick it up. Baling twine is easy to pick up … just keep your horse pastures free of baling twine,” Davis said. “It should be against the law to leave it out.”
The Audubon Society in Montana has sponsored efforts to collect baling twine, Davis said. Collection campaigns can be “a great community thing,” and something children enjoy helping with, she said. “You just get the landowners’ permission.”
Leigh said she is hoping something similar can happen here “to clean up areas known to have a lot of this type of debris.”
She sent her photos to WDFW and local Audubon Society members to draw attention to the problem, and hopes to raise awareness among the general public.
“It’s as vivid as seeing water birds tangled in fishing line or six pack rings,” Leigh said. “It’s not a local issue, it’s a national issue and probably a worldwide issue.”
“We humans are very compassionate about the animals around us,” Woodruff said. Incidents like the dead osprey photographed by Leigh “are disturbing moments in our interaction with the animal world.”
Ospreys, like other birds of prey, “were severely affected by DDT [a pesticide] so their populations were significantly diminished” before the chemical was banned in the early 1970s, Woodruff said.
The osprey population has rebounded since then, he said, and the raptor is not listed as threatened or endangered. Woodruff estimated that perhaps 10 pairs of ospreys live in the Methow Valley. One pair has nested for several years near tennis courts on the Methow Valley school district campus.
Ospreys usually mate for life, Davis said. Sometimes called “fish hawks,” ospreys eat fish almost exclusively, and build their nests near rivers, lakes and salt water.
The females stay in the nest after chicks hatch, and the male catches and delivers fish. In fall, the birds migrate south to Mexico, Central America and South America. The adults leave first, and the “young figure it out” and follow soon after, Davis said.