Yellowstone…Where Are The Wolves?

Image from winter 2010

While each visit to Yellowstone is amazing. It is different each year too. The temps can range from breathtaking -40 degrees to balmy temps in the 30’s. The snow depth varies each year too. How does this impact the wildlife? Do they prefer cold temps? How much snow is too much for them to survive? This year the wildlife in Lamar Valley was not as plentiful as previous years. The wolves were farther off in the distance and there were some days when I dare say the wolf watchers didn’t even wee them. Each trip we speculated as to why. Yesterday Barry sent me an article by Dr Jim Halfpenny that explained the situation and in fact gave dire predictions for both the grazers as well as the wolves. Here is a small excerpt of the article…

“This year’s snowpack is dramatically different from all the years I have collected data at these locations.
The impact of the 2011 snowpack on grazers is evaluated by what I call red line values. Snow becomes a critical limiter when it reaches chest height of an animal. The red line value for chest height for bison is 26 inches and for elk 33 inches. On the Lamar Valley bottom, the snowpack depth is the greatest since I start at 38 inches (96 cm). Other red line values are a density of 30% water and a Snow Water.
The statement is often heard that a “tough” winter on grazers is good for wolves. But this winter a threshold of food availability may have been crossed and wolves may starve to death. Yes, wolves can starve!
Copyright by Jim Halfpenny, Feb. 7, 2011.

To read the article in it’s entirety go here. There is a $20.00 membership fee to get the reports but, if you are interested in the goings on in Yellowstone, it’s worth the cost!