texascavers Digest 14 Nov 2010 06:57:38 -0000 Issue 1192
Topics (messages 16511 through 16511):
Cave Owl regurgitations are clue to climate change :
16511 by: JerryAtkin.aol.com
Administrivia:
To subscribe to the digest, e-mail:
<[email protected]>
To unsubscribe from the digest, e-mail:
<[email protected]>
To post to the list, e-mail:
<[email protected]>
----------------------------------------------------------------------
--- Begin Message ---
Owls' clue to climate change
UTAH | Analysis of 13,000 years of prey shows impact on ecology
November 13, 2010
BY BRIAN MAFFLY
Homestead Cave, at the north end of Utah's Lakeside Mountains, has yielded
a paleontological jackpot for scientists reconstructing ancient Great Basin
environments, thanks to owls that spit up small-animal prey there for
thousands of years.
The piles of regurgitated pellets drew Dave Madsen in the early 1990s,
hoping the bones would provide a record of plants and animals.
Madsen and his colleagues found scientific pay dirt. Three years of
excavation recovered undisturbed bones representing what has been on the owls'
menu for the last 13,000 years.
The resulting millions of tiny bones and dirt help young researchers study
how the local ecology responded to past climate change.
"It's an amazing record. It's still giving us so much information, and the
whole strata have not been studied yet," said Rebecca Terry, who began her
work here as a University of Chicago graduate student.
Anthropologist Don Grayson, working with Madsen, examined 186,000 tiny
bones from 22 species of small mammals. Terry ran with Grayson's findings,
winning the Society of Vertebrate Paleontology's Romer Prize.
Terry trapped small animals around the cave and compared them with what the
owls had spit up. She found the animal population fluctuated in close
association with climate changes going back thousands of years.
When temperatures tended warm, southern-leaning rodent species
predominated, she found. Their northern cousins were more abundant in colder
temperatures.
These findings can help biologists predict how warming expected in the
coming decades will affect Great Basin animal communities and develop
conservation strategies, Terry said.
_http://www.suntimes.com/news/nation/2891388,CST-NWS-owl14.article_
(http://www.suntimes.com/news/nation/2891388,CST-NWS-owl14.article)
--- End Message ---
