10 things you didn’t know about Gyrfalcon

Stocky, powerful, and beautiful, Gyrfalcon is, indeed, the ultimate falcon. No wonder our readers voted it one of the birds they want to see most.

It makes its home all around the top of the world, breeding in Greenland, Iceland, Norway, Finland, and Russia, as well as North America. But in winter, when the weather turns brutal and sunlight becomes scarce close to the pole, it migrates.

Adult males remain mostly within the southern part of the breeding range, but adult females and immature falcons fly farther. They may show up anywhere across the northern United States.

As wildlife biologist Dick Dekker explained in a fascinating article in our December 2011 issue, most sightings are from coastal areas — but not all of them. The winter of 2013-14 has been no different.

According to eBird, Gyrs were reported near Wallowa Lake, in eastern Oregon, in January and at the Eel River Preserve, south of Eureka, in northern California, in early February. One was spotted sitting on a hay bale, sheltering from the wind, just outside Pierre, South Dakota, while another, a big gray morph, was seen winging over Buena Vista Grasslands in Portage County, Wisconsin, on January 25.

East Coast birders photographed one on Hampton Beach in Rockingham County, New Hampshire, on December 15, just a few days after another was reported on Cedar Beach Marina on Long Island, New York.

Have you seen a Gyrfalcon this year? Here are 10 little-known facts about the species to consider while you look:

One

The name Gyrfalcon may be a hybrid of the Old High German word gir, meaning vulture, and the Latin falx, a farm tool with a curved blade, a reference to the bird’s hooked talons.

Two

The connection to old languages seems appropriate since scientists recently documented the falcon’s reliance on and continued use of old nesting sites in Greenland. In the island’s cold, dry climate, guano and other nest debris decay slowly. Researchers visited 13 nest sites, tested the age of the droppings, and found that four sites had been in use for at least 1,000 years.

Three

The oldest nest had guano deposits dating back as much as 2,740 years.

Four

They are among the longest used raptor nest sites ever documented.

Five

Research on Greenland’s Gyrs has also revealed that they spend much of their winters on sea ice far from land, most likely pursuing seabirds and ducks.

Six

A 2007 study of Gyr DNA found that populations in Greenland and Iceland are genetically distinct. In addition, birds nesting in Norway, Canada, and Alaska form a single population, most likely involving Russian Gyrs as well.

Seven

During breeding season, the falcons occur in alpine and arctic tundra habitats, often near rivers and coastlines, and they rely heavily on ptarmigan for food.

Eight

In fact, Gyrfalcon’s breeding distribution across the Northern Hemisphere is strikingly similar to that of Rock Ptarmigan.

Nine

Recent research from Canada’s Yukon Territory, however, suggests climate change may be disrupting the age-old relationship of predator and prey. Until the year 2000, 10-year population cycles had been observed in Willow Ptarmigan and Gyrfalcon, but in the last decade, “ptarmigan abundance may be faltering,” writes Dave Mossop of Yukon College. The population peaks, he adds, “seem to be disappearing, although there is no evidence of imminent local extinctions.”

Ten

In turn, he says, “Gyrfalcons are breeding much later, may be producing fewer young, and seem to be declining in abundance.”

Read “Ultimate Falcon,” Dick Dekker’s article about Gyrfalcon.

Read about the top 10 most-wanted birds in the U.S. and Canada.

 

Originally Published February 12, 2014