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A wildlife researcher from Nevada has discovered that even the fastest bird on Earth can escape mercury contamination.
The toxic element appears in the feathers of peregrine falcons from coast to coast, including those in the Mead Lake National Recreation Area, Joe Barnes, a biologist with the state's Wildlife Department.
In the last ten years, Barnes has analyzed mercury in 700 pilgrims in southern Nevada, Washington, Maryland, and the Texas Gulf Coast.
Each of them was hit, whether they live in a wilderness, in Lake Mead, in Greenland or on the coast of British Columbia, he said.
Barnes' latest findings were published in February in the Journal of Raptor Research.
Further research is needed to determine how much Mercurial Peregrine Falcons can tolerate, Barnes said. But studies on other raptors suggest that concentrations of between 5 and 15 parts per million can significantly reduce reproduction.
Barnes documented mean mercury concentrations of 17 ppm in adult pilgrims from Mead Lake near Las Vegas and 23 ppm in adult pilgrims from the Washington Coast. Even hawks migrating from Greenland, Alaska and northern Canada to the south, far from industrial sources of pollution, carry an average of about 10 ppm of mercury in their feathers, he said.
Pilgrims are one of the most affected species in terms of contamination, says Barnes, as they feed on other birds exposed to mercury.
At Mead Lake, the pilgrim's favorite prey is the grebe, a small aquatic bird that migrates through the region in the hundreds of thousands.
Barnes said that most Grebe Lake grebes also spend time in the mercury laden waters of the Great Salt Lake.
The peregrine falcon hunts almost everything that flies, including birds and bats. He dives over the prey with the wings closed, which allows him to reach a speed greater than 328 km / h.
Barnes has described pilgrims as an indicator of the overall health of the ecosystem because they are found on every continent, with the exception of Antarctica, and feed on them. a wide variety of species, from bats to hummingbirds, to geese.
Ryan Bourbour, a biologist and doctoral student at the University of California at Davis, has also studied mercury exposure among raptors in North America. He added that even low exposure can affect the health of humans and wildlife.
Assessing exposure levels in large predators, such as peregrine falcons, can have implications for conservation and even human health, he said.
In the United States, most humans exposed to mercury feed on fish containing methylmercury, which forms when bacteria react with mercury in water, soil or plants. Elemental substances and methylmercury are toxic to the nervous system and the inhalation of mercury vapor can cause various symptoms or even death.
Until now, the hawks Barnes studies show no adverse effect of exposure.
He said he identified more than 90 different prey species from feathers collected at hawk nesting sites around Mead and Mohave lakes.
Although mercury is naturally present, research suggests that levels have increased by 300% since the start of the industrial revolution in the late 1700s.
The pilgrims are in a way the canary of the coal mine here, he said.
Information from: Las Vegas Review-Journal,
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