Friday, January 27, 2012

Killing owls to save owls

Here's a link to an article on about the threat that barred owls pose to the continued survival of spotted owls in the Pacific Northwest.

Three-week old spotted owl hatchlings

An excerpt from the article:

Most of the evidence that barred owls are harming spotted owls is circumstantial; that's why Wiens and other researchers traipse the woods daily, studying how the two species fight for space and food. Still, the trend is clear. Rocky Gutiérrez, a University of Minnesota wildlife biologist, wrote in 2006 that "despite the paucity of information, many biologists now feel that the barred owl is the most serious current threat to the spotted owl."

Both barred and spotted owls, along with great gray owls and rufous-legged owls, belong to the genus Strix, medium-sized birds that lack the hornlike tufts of ear feathers common to many other owls. They are so closely related that they sometimes crossbreed, blurring species boundaries and diluting spotted owl genes. More often, though, when barred owls move in, spotted owls just disappear.

Where spotted owls are finicky eaters, barred owls consume almost anything, including spotted owls. Barred owls, typically 20 percent larger than their rivals, may take over spotted owl nests or slam into their breasts like feathery missiles. "The barred owl is the new bully on the block," DellaSala says. A few years ago, a naturalist in Redwood National Park observed the aftermath of a murderous encounter: a barred owl with a tuft of mottled feathers clinging to its talons flapping near a decapitated, partially gnawed spotted owl. When scientists dissected the spotted owl's body, they saw that it had been sliced and perforated, as if by talons.

So in recent years, wildlife managers have been mulling the ethics and efficacy of culling the barred owl in order to protect the spotted owl:
When barred owls started moving into spotted owl habitat, the U.S. Fish and Wildlife Service initially proposed killing hundreds of the invaders. After an outcry from scientists and the public, wildlife managers instead plan to launch smaller studies to see if culling barred owls prompts the spotted birds to return. Even proponents of the approach acknowledge that the idea raises a thorny question: When is it appropriate to kill one species to help another?
A fascinating controversy continues! And . . . never too early to think about term paper topics.

Saturday, January 21, 2012

Welcome to spring 2012 semester

Hi everyone,
welcome to the course blog for NTRES 2320, "Nature and Culture." Looking forward to reading your postings.