Eagles and ospreys are flying pack rats

There's a rumor making the rounds that 51 dog and cat collars were found in the debris of a fallen eagle nest.

Someone told someone who told me. They even placed the story in western Hennepin County, but I'll be darned if I can find the source.

It may be nothing but a suburban legend, but it sparked some lively online conversation about the likelihood of Fifi becoming dinner for a nest of baby bald eagles. And I got an earful of entertaining stories about the pack-rat tendencies of ospreys as well as eagles.

Flying dogs

According to a recent story in Alaska Wildlife News, the size of most dogs rules them out as eagle prey.

The weight that bald eagles can carry on the wing is a factor of aerodynamics, writes Riley Woodford. A grounded eagle is unlikely to pick up and fly away with anything weighing more than 5 pounds. A swooping eagle could carry off something weighing slightly more, say 6 or 8 pounds.

Cat are more likely to be eagle targets, wrote Woodford, who found an unbuckled cat collar with a bell attached in an eagle nest. Woodford said that while the cat may have been scavenged roadkill, mink, muskrat and sea otter pups have been verified as eagle prey in Alaska.

But dogs? Woodford thinks eagles are too people-shy to attack a dog on a leash.

Madeleine Linck, a biologist with the Three Rivers Park District, disagrees.

"The idea of dog collars in an eagle nest may not be too far-fetched," she said. "A neighbor of mine two springs ago had a mature eagle land in her front yard in front of her old white Spitz. The dog was sleeping in the sun on her leash. The dog was quite deaf, but woke up when the eagle began walking right up to her. My friend was amazed, watching through the kitchen window. The dog started barking. That sent the eagle off," Linck said.

When I asked a friend who works at New York's Cornell Lab of Ornithology if she thought an eagle could whisk away a 12-pound dog, she answered me with a "nope. The eagle would kill it and eat it right on the spot," she said.

The writing of Arthur Cleveland Bent supports that. Bent, author of a fascinating series of biological profiles of North American birds, says that bald eagles have been known to attack domestic dogs, and that both dogs and cats are among the mammals a golden eagle would attack.

Birds and bikinis

Even if eagles may not fly home with a dog or cat, it's clear that some birds of prey pick up rather unusual items.

"Ospreys and eagles are notorious for bringing stuff into their nests," said Mark Martell, director of bird conservation for Audubon Minnesota. "I remember finding a lacy black bra in an osprey nest on a platform in a friend's yard. She [the friend] insistently maintained the undergarment was not hers. And some years ago we found the top and bottom to a bikini in an eagle nest on the Mississippi."

Martell added that a birding buddy in Finland once found a garden gnome in an osprey nest.

Bent has a compiled a list of items found in osprey nests. In addition to shoes, pants and a rubber boot, it includes roof shingles, a boat rudder, a toy boat with sail attached, a broken hand ax, a feather duster and a rag doll.

No bikinis were noted.

Jim Williams, a member of the American Birding Association, Ducks Unlimited, Pheasants Forever and Delta Waterfowl, can be reached at two-jays@att.net. Join his conversation about birds at www.startribune.com/wingnut.