(UPDATED*) Bozeman Daily Chronicle: A feel-good story bites the dust? Scientists say Yellowstone wolves did not scare elk into letting aspen grow back
Just one popular media reporter, far as I can tell, has so far perked up at news that an often-cited trophic cascade in Yellowstone Park, one embraced by partisans of reintroducing wolves to the area a few decades back, may not have happened. At the Bozeman Chronicle, Daniel Person explains it without once foisting the term “trophic cascade” on his Montana readers (I think he might better have slipped it in, just for edification).
It’s not a long story but important for public update on what had become a minor scripture among groups hoping to see wolves restored to as much as possible of their original range. It goes like this: wolves, by culling elk and making the rest of them skittish, are keeping the hefty browsers out of confined areas where they have a hard time seeing the lupine carnivores in time to get away from them. Such places include narrow riparian corridors, ravines, and other places where, reportedly, aspens and other native vegetation are again thriving in the manner of the time prior to wolf eradication. This in turn means more habitat for a panoply of other plants and wildlife. So researchers said.
This week in the journal Ecology however other researchers, with the US Geological Survey and University of Montana, report that the effect may be real but is much smaller than had been supposed. It would, they suggest, take a lot more wolves than now range the mountainous region to shift elk browsing very much. They say it’s number of elk, not a climate of fear, that controls how many aspen saplings they kill. None of the aspen groves that were nibbled to nubs in the last century by burgeoning elk, he reports, have regenerated.
This is fascinating for both scientific, or range management, reasons and for political ones. There probably are powerful rewards to having more wolves in the Montana-Wyoming-Idaho area than there are now, and certainly not fewer of them. But perhaps the simple cause-and-effect vision of a verdant, restored aspen ecosystem is in fact oversimplistic. The news got spread widely, via press release as seen below in Grist. My bet is that other outlets, perhaps weeklies and others plus specialty publications and blogposts, will circulate it further.
Person appears have some of his history incomplete. He dates the wolf-elk-aspen hypothesis to a paper published in 2007 that “fleshed it out.” But it was in circulation (and influential) well before that – as in this abstract from the December, 2001 issue of Biological Conservation. I recall first hand, from an interview in 2006 for a story on another topic, that one of the co-authors of the 2001 paper, Yellowstone wildlife biologist Roy Renkin, was already sure that other factors – drought maybe – had confounded the data.
*UPDATE – other media coverage has arisen:
- BBC – Mark Kinver : Wolf re-introduction fails to stop elks eating aspens ;
Grist for the Mill: USGS/Ecological Soc’y of America Press Release ;
Other wolf news – That federal judge’s ruling taking wolves away from state authority and putting them back under protection of the federal Endangered Species Act, continues to get heavy regional attention.
- Missoulian – Rob Chaney: Wolf, grizzly bear cases set back progress, biologists, managers say
- Idaho Mountain Express – Katherine Wutz ; Agency: Manage wolves more aggressively/ Sterilization, gassing of pups proposed ;
- Clark Fork Chronicle: Baucus presses for state control over wolves ;
- Public News Service – Deb Courson: Wolf Depredation Funding Shift Becomes a War of Words ;
- AP – Ben Neary: Wyo. not inclined to act on wolves ; That’s unless shooting them on sight is considered action.
- Charlie Petit
