Warning. Bison migration across US 191 north of West Yellowstone!

Sudden appearance of bison on highway have resulted in numerous bison deaths-

Although conditions for the bison that leave west side of Yellowstone Park in the winter, and especially the spring, have been much better in 2009, the sudden migration of buffalo across busy U.S. 191 has resulted in at least 15 dead bison this week. Fortunately, human injury has been minor. The bison are heading for Horse Butte where they calve on its sunny south-facing slope.

The great danger is at night. That is when these wrecks have happened. Bison on the highway are all but invisible in the dark, and they generally don’t move when they see on-coming headlights. Unlike elk and deer, their eyes don’t glow in the headlights. They don’t have a light rump patch like elk.

The bison don’t just cross the highway. They eat the grass on the edges and linger because the warmer roadside is one of the first places grass sprouts in the spring. This year the snow is staying longer than usual due to wave after wave of storms with heavy wet snow.

When bison are on the road, or likely to be, the Buffalo Field Campaign deploys a number of volunteers to slow traffic down, warn them, etc. They have a number of pink neon signs that read “Buffalo Crossing.” They patrol day and night, although 24-hour-a-day coverage is not possible. Moreover, BFC has no official capacity, so they cannot haze the bison off the highway. The result can be frustration among motorists waiting for the bison to move off the highway. Read the rest of this entry »

Study to probe effect of climate change on Yellowstone grizzlies

The less time in the den, the more bears are killed, especially in the fall-

Although grizzlies are now coming out of their dens, quite slowly this year because of deep snow, it may be that recent warm years have delayed the onset of their annual winter hibernation.

Now a study is underway to ascertain the details of den entrance and emergence and compare them to temperature and snowfall.

Autumn is the most dangerous time for the grizzly, doubly so now with the decline in high altitude whitebark pine nut “crop” due to the hot fires of 1988,  the spread of whitebark pine blister rust (a non-native disease) and a general die-off of pines of all species in the Rocky Mountains.

The longer bears are denned up, the fewer are killed during the year.

Study to research effect of climate change on denning. By Karl Puckett. Great Falls Tribune Staff Writer.