The 18 most-wanted birds in North America
Gyrfalcon
1. 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. 2. 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. 3. The oldest nest had guano deposits dating back as much as 2,740 years. 4. They are among the longest used raptor nest sites ever documented. 5. 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. 6. 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. 7. 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. 8. In fact, Gyrfalcon’s breeding distribution across the Northern Hemisphere is strikingly similar to that of Rock Ptarmigan. 9. 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.” 10. In turn, he says, “Gyrfalcons are breeding much later, may be producing fewer young, and seem to be declining in abundance.”
1. 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. 2. 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. 3. The oldest nest had guano deposits dating back as much as 2,740 years. 4. They are among the longest used raptor nest sites ever documented. 5. 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. 6. 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. 7. 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. 8. In fact, Gyrfalcon’s breeding distribution across the Northern Hemisphere is strikingly similar to that of Rock Ptarmigan. 9. 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.” 10. In turn, he says, “Gyrfalcons are breeding much later, may be producing fewer young, and seem to be declining in abundance.”
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