Flip through a field guide to western birds and you'll discover the great gray owl occupies the narrowest of ecological niches in California: dense conifer forests next to moist mountain meadows.
But lately, the elusive owl has been spotted swooping through much different terrain: the sun-baked Sierra Nevada foothills where - surprisingly enough - it is thriving on land owned by the state's largest timber company, Sierra Pacific Industries.
The bird's discovery south of Placerville has startled wildlife biologists and bird-watchers who have long considered the exceedingly rare, brownish-gray owl to be a stalwart of higher elevations, a winged icon of the wilderness.
"It's pretty exciting they are being found this low," said Graham Chisholm, executive director of Audubon California. "It shows the resilience of these birds."
It has also sparked speculation about when the birds arrived, where else they may be hiding and why they are homesteading scruffy oak and pine foothill forests, including areas recently logged by Sierra Pacific.
"This may be a case where management on private land is providing more suitable habitat than public land," said Chris Stermer, a wildlife biologist for the California Department of Fish and Game. "We just don't have enough information to say for sure."
This much is certain: With a wingspan wider than a car door, piercing yellow eyes and a face as round as a dinner plate, the great gray owl is not just the largest owl in North America but perhaps its most majestic, too.
In flight, it glides though the forest, rarely flapping its wings, so silent and smooth it's been called the great gray ghost. "It's such an unbelievably charismatic bird," said Chisholm, who recently saw two great gray owls - an adult and juvenile - on a visit to the Sierra Pacific site. "It's awe-inspiring to be around them."
Perched on a branch, the owls are typically still as statues and next to invisible. "I have a picture of a bird in a cedar and unless you know it's there, you cannot see it," said Kevin Roberts, a wildlife biologist for Sierra Pacific. "It's a full-grown adult sitting there looking at you."
Unlike spotted owls, which respond readily to a biologist's call, great gray owls are wary of people and not easily fooled. "They are so hard to find," said Stermer. "There have been a lot of frustrating times. Every once in a while, I think if I could just go out and count deer, that would be a good change."
They appear to be clever, too, even manipulative. On occasion, Stermer has watched, astonished, as a great gray owl has flown through the forest ahead of him, deliberately leading him away from its nest.
"It's happened enough times that it's apparent they are truly leading you away," Stermer said. "They know you are following them."
Only 200 to 300 great gray owls are estimated to be in California, so few that they are on the state endangered species list. For years, Stermer has struggled to find more, searching in places where the field guides and scientific studies say the owls live: dense stands of conifer near lush, green mountain meadows.
That changed in 2006 when a Sierra Pacific forester named Lance Purdy was marking trees for a timber sale outside Placerville. He spotted a large owl with a round face in a gnarled black oak snag and called Roberts, the SPI biologist.
"He said: 'I found a great gray owl,' " Roberts recalled. "My response was: 'No, you didn't.'
"He said: 'Yes, I did.'
"I said: 'OK, I'll go check.' "
Not only was the bird a great gray owl, it also was tending a nest with its mate, and two young birds. Soon, Roberts was calling the owls by a new name: Purdy's birdies.
"They are not supposed to be here," Roberts said. "This is not classic habitat."
Since then, two more pairs of great gray owls have been found on the company's sprawling 17,000-acre property near Mount Aukum. In all, they have produced at least 28 young. Because only a fifth of the land has been surveyed, Roberts believes more are likely to be found - perhaps a lot more.
A handful of other owls have been spotted elsewhere in the foothills, one within hooting distance of a winery near Fair Play and a breeding pair near Pliocene Ridge in Yuba County.
"This is a wonderful discovery," wrote John Muir Laws, author of the "Laws Field Guide to the Sierra Nevada," in an email. "It reminds me of a saying of the great birder Rich Stallcup: 'When the bird and the book disagree, believe the bird.'
"We falsely assume we already know the important things about nature and can look it up," Laws added. "However, as this owl proves, there is more we do not know than we can conceive and nature reserves the option to change her mind."
One of the biggest surprises is the owls' proximity to logging operations. They seem unperturbed by the whine of chain saws or the sunlit openings created by selective harvests and small clear-cuts. They have sometimes even nested close to such areas.
"Timber management and wildlife management are not mutually exclusive," Roberts said. "You can do both.
"Obviously, we've got something going on here," he said. "The birds are here. They reproduce every year. We know our management hasn't chased them away."
Nonetheless, SPI is not taking chances. If an owl is found near a logging site, logging stops. "If they're there, we protect them," Roberts said.
One of this year's nesting sites lies close to an old logging site in a dense tangle of oak and pine along an ankle-deep creek. The nest itself is in an enormous moss-covered white oak, so gnarled it reminds one of J.R.R. Tolkien's fantasy forest of goblins, hobbits and dwarves.
On the side of the tree is a sign that says: "Wildlife Tree. This tree has special value to wildlife. Please protect it. Sierra Pacific Industries."
That chaos of limbs, branches, leaves and trees is more than a critical nesting place for great gray owls. It is also a life-saving jungle gym for their young.
"When the owls take their first flight, they often miss a branch and find themselves on the ground," Stermer said. "The only way to get back up is to find a low branch where they can actually climb up. Otherwise, they would just turn into bait for some other animal."
Stermer said he is concerned that great gray owl habitat along the edges of meadows in national forests is sometimes logged more intensively. "To reduce the risk of fire, they cut the lower branches off and clear the understory," he said.
And he worries that livestock grazing in some areas, including Lake Davis in the Plumas National Forest, is harming the rich carpet of meadow grasses that shelter the rodents the owls eat, potentially robbing them of protein.
"On some of these public lands they really do graze them heavy," he said. "That has the potential to reduce cover, forage opportunity and prey base."
John Heil, a spokesman for the U.S. Forest Service, said the agency is preparing an environmental assessment of grazing in the Lake Davis area. "We are looking to analyze and mitigate effects, when necessary, to potentially affected resources, which include the great gray owl," Heil said.
The thickets of oak and pine in the foothills are also great hiding places, so shadowy and impenetrable that great gray owls may have been swooping through them for centuries and simply haven't been seen.
"My best professional judgment is they're not moving, that they have been nesting in these areas and we just haven't detected them," Stermer said. "Animals don't typically move and inhabit new habitats."
Because the region is largely private land, it's long been overlooked by naturalists drawn to more scenic and accessible public land at higher elevations.
"We think of great gray owls as a High Sierra meadows bird, in part because maybe that's where we love going," said Chisholm, the Audubon California director.
"The fact that they are showing up in places we don't expect is in keeping with the mystery of the owl."
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