Monthly Archives: October 2014

Highways, Genes and So. Cal. Mountain Lions

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UC Davis mountain lion geneticsThe mountain lions of southern California are hemmed in on all sides. In one place a 10-lane highway divides mountain lion habitat. All that development is particularly difficult on a species with such a large home range.

All those highways and housing developments are putting a crimp in the mountain lions of the region’s gene pool, says a recent paper in PLoS ONE by University of California, Davis scientists. The mountain lions of the Santa Ana Mountains are no longer on speaking terms with the mountain lions of the Santa Monica Mountains. Within those population segments, genetic diversity is low.

I just covered this issue back in January (where the solution was a wildlife crossing) and wasn’t sure it was worth writing about again, but a the UC Davis press release and a Los Angeles Times article pointed out that we’ve seen this phenomenon of mountain lions hemmed in by a growing human population before — in the Florida panther. Other Puma populations may not be as distinctive as the Florida panther, but we are almost certainly sure to see this again. If there is a solution, it is a story worth following.

Read the PLoS ONE paper here.
Read the UC Davis press release here.
Read the Los Angeles Times story here.

Photo/map: This map identifies puma captures in the Santa Ana Mountains and eastern Peninsular ranges of southern California. The inset photo is of a mountain lion keeping watch while her juvenile cubs feed. Courtesy: UC Davis/The Nature Conservancy

Bats Think Wind Turbines Are Trees

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wind Turbines credit Joshua WinchellWhy migrating, tree-roosting bats are more susceptible to being killed by wind turbines has been a mystery. In a recent issue of the Proceedings of the National Academies of Science (PNAS), US Geological Survey scientist Paul Cryan offers an explanation: under certain wind conditions, the air currents around turbines is similar enough to the air currents around trees to confuse the bats into thinking the turbines are big trees.

The paper says that the bats congregate on the downwind side of trees to feast on the flying insects that congregate there. The paper doesn’t make this comparison, but it’s a lot like trout hanging out in an eddy, waiting for insects and other edibles to join them.

The problem, of course, is that spinning blades and barotrauma are not kind to bats that hang around wind turbines.

Two of the take-aways from the paper are that turbine operators can put bat deterrents on the downwind side of the turbines, and that changing the operating parameters of the turbines could help save bats, such as preventing the blades from turning in a sudden gust on an otherwise calm night.

Read the PNAS paper, here.
Read a Washington Post paper on the study and the white nose syndrome threat, here. (But note that it never mentions that one group of bat speices is more vulnerable to white nose syndrome, while a different group of bats is more vulnerable to wind turbines.)
A summary of the paper in the Discover Magazine blog is here.
A different summary of the paper in the Popular Science blog is here.
And just for good luck, here is the write-up from Conservation Magazine.

Photo: Instead of going with a generic bat photo, since I don’t seem to have any of common migrating bats, I went with a generic wind farm photo. This is not the wind farm that was studied in the Cryan paper. Lovely photo by by Joshua Winchell.

Oregon Introduces Online Elk Hoof Disease Reporting

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Hunters have been turning up elk with deformed hooves in southwest Washington for nearly 10 years. In the past six years or so, the numbers of those reports have increased. The first reports of elk hoof deformities in Oregon were reported this summer,The Oregonian reported.

This week the Oregon Department of Fish and Wildlife announced an online reporting system to make it easier for hunters to report elk with deformed hooves, so that the department can track the deformities in northwestern Oregon. The online form also requests that the hunter take pictures of the hooves, wrap them in plastic bags and store them in a cool place for further examination later.

For many years, the cause of the elk hoof deformities was a mystery. Today the Washington Department of Fish and Wildlife believes that treponemes, spiral-shaped bacteria, likely cause the disease, according to the article in The Oregonian. Livestock have a similar disease, the article says.

Read the Oregon Department of Fish and Wildlife press release, here.
Read the August article from The Oregonian, here.

Half as Many Animals Today as 1974

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living planet reportA new report from WWF says, “Population sizes of vertebrate species measured by the Living Planet Index have halved over the last 40 years.” Worldwide, it’s freshwater species that are feeling the the most pain, with populations declining 76 percent. Latin America is the world region with the steepest decline, with populations falling 83 percent.

High Country News summarizes what the report says about the United States, specifically the western US succinctly. We’re good at preserving charismatic megafauna — bison are up, even wolves are. But we’re not so good at the little things, like amphibians. Our wealth as a nation means we can pay to protect the wildlife we love, but it also means we can outsource our exploitation — such as when we save the fish on our own coasts, but import most of the fish we eat from elsewhere.

Download the Living Planet Index, here. (Part of a larger Living Planet Report.)
Read the High Country News coverage, here.