U.S.-Mexico border fence isolates wildlife

Walls built along the U.S.-Mexico border don't just keep human families apart.

Biologists say the barriers also threaten such wildlife species as bighorn sheep and pygmy owls, isolating populations and narrowing the gene pool. Pygmy owls, who sometimes fly low to the ground, may find their flight patterns disrupted by high fences or walls.

"This has happened so fast, there was no time for a pre-fence study," said Clinton Epps, a wildlife biologist at Oregon State University and a co-author of the study. A break in the fence in key places could allow for greater genetic diversity among bighorn sheep, Epps said.

Constructing poles for owls to perch on and maintaining brush and tall trees around the border could support pygmy owls, according to Aaron D. Flesch, a biologist from the University of Arizona and the lead author of the study.

"Movement of pygmy owls from Mexico to Arizona may be necessary for the persistence of the Arizona population," Flesch said.

The results of the study were published in the journal Conservation Biology.

-- Amy Littlefield

Photo: A bighorn sheep and her lamb in the Rocky Mountains in Wyoming. Credit: Anacleto Rapping/Los Angeles Times

Comments

[JOE SERRANO]

HELLO IAM JOE SERRANO I HAVE A HOME FOR ALL OF OUR BORDER WASTE TEXTILE SCRAP WASTE FROM (SOLID WASTE) OUR (NAFTA) MEMBERS(1000) THOUSANDS OF TONS ARE BEING DUMPED IN OUR OCEANS AND LANDFILLS WHEN I CAN RECYLE THIS AND NO ONE SEEMS TO CARE WHEN IT TAKES UP TO 20 YEARS TO DISSOLVE FROM OUR PLANET WHICH ALL THREE COUNTRIES IGNORE USA MEXICO AND CANADA PER OUR TRADE AGREEMENT ITS IS SUPPOSE TO BE DUPED OR RECYLED THANK YOU MUCH JOE SERRANO 323 289-8147 ENVIROMENTAL COMPLIANCE ISSUE

[Jim Smith]

Dick, the Ignorant Ditto-head: Spotted Owls are in worse shape than ever. Their population is still in steady decline. If you were not so stupid/close-minded, you would realize that species don't go extinct in the blink of an eye - it is a gradual process. Do some research and learn the truth, instead of spouting falsehoods.

Also - the reason Northern Pygmy Owls stay low to the ground or very close to cover is that larger owls (such as the Great Horned Owl) prey upon them. Having unbroken border fences with denuded surroundings (i.e. no brush near the fence) sets up a 'biological barrier' to the Pygmy Owls. Some may indeed make it across, but many will be deterred by their instinctive aversion to flying high / through clear areas. Others would undoubtedly fall prey to Horned Owls and perhaps Barn Owls, which would learn to stake out the fence area to catch wildlife trying to pass (or that pauses in confusion).

[Chris Clarke]

Yes, Dick. The scientists publishing in the peer-reviewed journal Conservation Biology know way less than you do about desert wildlife conservation, because you grew up in the woods. You tell 'em!

If anyone tries to suggest that the desert and the woods are two different things, you can just call 'em socialists. Or something. Don't you let the so-called experts take away your right to make statements out of ignorance! This is America!

[dick radatz]

Are you really so ignorant of nature that you think the owls would not fly over the fence? The spotted owl was going to disappear also wasn't it!! I grew up in the woods, and the total lack of knowledge and common sense you so-called experts say simply astounds me !!! ps- the sheep will do just fine, thank you.