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  • Homing in on herons

    Biologists will survey great blue heron rookery sites in Southern Oregon and statewide to see how species is doing
  • River-runners who come upon a great blue heron along the banks invariably end up playing an accidental game of hide-and-seek with the majestic yet awkward bird.
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  • River-runners who come upon a great blue heron along the banks invariably end up playing an accidental game of hide-and-seek with the majestic yet awkward bird.
    After standing motionless as a boater floats nearby, the nervous heron will bolt skyward and fly downstream, afraid it's being stalked. Moments later, as the boat again approaches, the heron will consider its fears validated and fly farther downstream, only to repeat this paranoid hop-scotching again and again until it finally figures out it should fly upstream to apparent safety.
    "You'd think they'd fly behind you, but they always fly in front of you," says Karen Hussey, research and monitoring program manager of the Klamath Bird Observatory.
    Though the heron's suspicious mind-set is well known in the bird world, no one knows just how many of these anxious avians are out there. But field biologists across the West are now trying to find out.
    With the help of organizations such as KBO, they are fanning out across Oregon and 10 other states to quantify known nesting sites, called rookeries, of herons and a cache of other colony-nesting birds that until now have had no real census.
    Biologists will survey about 200 specific areas statewide for various species of herons, egrets, white pelicans, cormorants, Caspian terns and two species of gulls in what will be the U.S. Fish and Wildlife Service's first attempt to gauge the relative health of these colony-nesting birds.
    Counting known breeding pairs during the spring nesting season will provide baseline data which, when compared to historical data and future surveys at these same sites, will offer insights into whether these birds are trending up or down over time.
    "This is a snapshot in time," says Jenny Hoskins, a Fish and Wildlife Service biologist overseeing the Oregon part of the survey. "It gives us a starting point, baseline data, of what's out there."
    The data will help federal biologists make management decisions about these birds and help resolve potential conflicts between birds and people, Hoskins says.
    It can even quantify such things as how expanding populations of bald eagles are affecting herons, which eagles tend to chase away from their nesting grounds, she says.
    "We've done surveys in bits and pieces, here and there," Hoskins says. "This is the first real comprehensive survey on them."
    Over time, biologists hope to estimate the minimum regional population size of the various breeding waterbirds in the 11 Western states and produce an atlas of these breeding colonies in 2012, Hoskins says.
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