AUBURN — The birdnest Robert Crosby found is a curiosity — intricately woven of fine threads of plastic fiber that make it nearly indestructible.

But the monofilament fishing line the birds used in the nest was most likely also deadly, strangling the hatchlings it was meant to protect.

“Once birds get tangled in fishing line, they are grounded,” Crosby said. “They are subject to predators at that point, or starvation. Either way, it isn’t good.”

Crosby, of Turner, is on a mission to keep it from happening again.

With the blessing of the Lake Auburn Watershed Commission, Crosby has constructed 12 white plastic tubes designed to collect discarded monofilament fishing line.

So far, 10 of the tubes have been placed in favorite fishing holes around Lake Auburn, within easy reach of area fisherman. Crosby hopes people will take the few extra steps to stuff their used fishing line in the tubes rather than let them littler the shore.

“It’s amazing the things people will leave behind — dirty diapers, beer cans and food wrappers,” he said. “But fishing line is the worst because it is so dangerous to the birds and other wildlife.”

Crosby is an avid bird watcher, kayaker and photographer. His favorite thing is to paddle around Lake Auburn, taking pictures of the local fowl and other wildlife.

“I always carry a Walmart bag or something to collect trash,” Crosby said. “Part of that is picking up the fishing line, too.”

He was collecting trash in some bushes off of North Auburn road when he stumbled upon the nest. It was a dried-out husk that had long been abandoned. He was fascinated by the way the bird had woven the fishing line into the nest.

“I tried to reach in and clear away some of the lines before I realized it was all in the nest,” he said. “It was the nest.”

It snapped off in his hand. Looking inside, he saw it contained some fine bones and feathers — he figures they were the remains of whatever inhabitants were trapped by the fishing line.

Birds normally use grass, horse hair and other strings to make their nests.

“But a monofilament line is different because it doesn’t degrade,” he said. “It’s going to be there forever. Also, it can be 15 feet long and that doesn’t happen with horse hair. The lines end up being too long for the birds to handle.”

Crosby said he saw similar recycling tubes around a lake in Florida and realized how easy they would be to make. He talked with watershed officials, and they agreed to buy him the materials if he’d assemble the tubes.

“He really took the project from start to finish,” said Mary Jane Dillingham of the Lewiston-Auburn Water Pollution Control Authority. “It’s the perfect example of a person volunteering for all right reasons. He didn’t just come up with the idea and tell us to go do it. He actually did it.”

The first debuted last fall north of Lake Auburn, to see how it would last over the winter, Dillingham said.

staylor@sunjournal.com