For Immediate Release:  Wednesday, 26 June 2013
Contact: Liza Lester (202) 833-8773 x 211; [email protected]


DECLINING FORTUNES OF YELLOWSTONE'S MIGRATORY ELK
Are human choices redefining the fitness of an ancient survival strategy? 
Ecologists debate new evidence in an ESA Ecology Forum


IN THE late spring, the 4000 elk of the Clarks Fork herd leave crowded winter 
grounds near Cody, Wyoming, following the greening grass into the highlands of 
the Absaroka Mountains, where they spend the summer growing fat on vegetation 
fed by snowmelt. It's a short trip (40-60 kilometers) by migratory standards, 
and by modern standards, uncommonly free of roads, fences, metropolitan areas, 
and other human-built barriers. But it crosses an important human boundary: the 
border into Yellowstone National Park.  

The costs of migrating to the high green pastures have lately outstripped the 
benefits, according to a research report in the June issue of the Ecological 
Society of America's journal Ecology, published last week.

Arthur Middleton and colleagues at the University of Wyoming, the Wyoming Game 
and Fish Department, and the U.S. Geological Survey reported that the migratory 
Clarks Fork herd has been returning to winter grounds with fewer and fewer 
calves over the last few decades. Herds that remain in the vicinity of Cody 
year-round have more surviving calves. Middleton et al. attribute the change in 
migration fortunes to climate change and a resurgence within the park of 
predators that hunt newborn elk calves.

In a Forum edited by Marco Festa-Bianchet, of the Université de Sherbrooke, 
Québec, five working groups of ecologists commented on the data, praising 
Middleton and colleagues' work, but, in some cases, challenging their 
interpretation. Middleton and colleagues addressed the commentary in a rebuttal.

To READ the full release with links to the papers: 
http://www.esa.org/esa/?p=8351 

For a longer version with links and more PICTURES:
http://www.esa.org/esablog/research/declining-fortunes-of-yellowstones-migratory-elk/


__________________________
__________________________
Liza Lester
Communications Officer
Ecological Society of America
1990 M Street, NW
Suite 700
Washington DC  20036

202.833.8773 ext. 211
[email protected]

http://www.esa.org/esablog/
@esa_org
__________________________

Reply via email to