The 18 most-wanted birds in North America
Spotted Owl
1. If you were to play a word-association game in which you tried to match bird species to the geologic wonders of the world, it’s a safe bet that Spotted Owl would not be top of mind when you heard “Grand Canyon,” yet owl-detection surveys suggest that more than 200 Mexican Spotted Owls live in Grand Canyon National Park. 2. It’s the most common owl species within the park. (There’s another word rarely associated with Spotted Owl: common.) 3. The bird uses “narrow, steep-walled canyons where ledges and caves provide cover from high temperatures, as well as nest sites and foraging habitat,” according to avian ecologist David W. Willey and biologist R.V. Ward. “In essence, complex, rocky terrain has been substituted for old-growth forest.” 4. Willey and Ward conducted their surveys by imitating the owl’s calls and listening for responses — a common survey method across the range of Spotted Owl. 5. A research paper published last summer suggests a better survey method is to familiarize dogs with the scent of owl pellets and let them sniff the forest floor. Invariably, the pooches found owls that vocalization surveys missed. 6. Over the last three decades, scientists have researched Spotted Owl so intensely that today it has the distinction of being one of the most-studied owls in the world. 7. About 10 years ago, biologists from the U.S. Geological Survey and the U.S. Forest Service investigated the genetic differences among the three subspecies. They found that Northern Spotted Owl is a true subspecies and that the California and Mexican groups, despite being geographically isolated from one another, form a second genetic subspecies. 8. Northern Spotted Owl, the researchers concluded, split from the California and Mexican group around 115,000-125,000 years ago. 9. At one time, California and Mexican Spotted Owls occurred together and went their separate ways only about 15,000 years ago. (Despite the genetic similarities, the researchers say it’s appropriate to continue managing the birds as separate subspecies.) 10. The genetic study also found that California and Northern Spotted Owls hybridize in the area where the two groups meet: the Klamath ecoregion of southern Oregon and northern California.
1. If you were to play a word-association game in which you tried to match bird species to the geologic wonders of the world, it’s a safe bet that Spotted Owl would not be top of mind when you heard “Grand Canyon,” yet owl-detection surveys suggest that more than 200 Mexican Spotted Owls live in Grand Canyon National Park. 2. It’s the most common owl species within the park. (There’s another word rarely associated with Spotted Owl: common.) 3. The bird uses “narrow, steep-walled canyons where ledges and caves provide cover from high temperatures, as well as nest sites and foraging habitat,” according to avian ecologist David W. Willey and biologist R.V. Ward. “In essence, complex, rocky terrain has been substituted for old-growth forest.” 4. Willey and Ward conducted their surveys by imitating the owl’s calls and listening for responses — a common survey method across the range of Spotted Owl. 5. A research paper published last summer suggests a better survey method is to familiarize dogs with the scent of owl pellets and let them sniff the forest floor. Invariably, the pooches found owls that vocalization surveys missed. 6. Over the last three decades, scientists have researched Spotted Owl so intensely that today it has the distinction of being one of the most-studied owls in the world. 7. About 10 years ago, biologists from the U.S. Geological Survey and the U.S. Forest Service investigated the genetic differences among the three subspecies. They found that Northern Spotted Owl is a true subspecies and that the California and Mexican groups, despite being geographically isolated from one another, form a second genetic subspecies. 8. Northern Spotted Owl, the researchers concluded, split from the California and Mexican group around 115,000-125,000 years ago. 9. At one time, California and Mexican Spotted Owls occurred together and went their separate ways only about 15,000 years ago. (Despite the genetic similarities, the researchers say it’s appropriate to continue managing the birds as separate subspecies.) 10. The genetic study also found that California and Northern Spotted Owls hybridize in the area where the two groups meet: the Klamath ecoregion of southern Oregon and northern California.
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11 June 2022
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