Count the Pikas

Migrating poleward is not an option for every critter that lives on the alpine islands of North America. Pika range is decreasing.

"They've been driven upslope a half mile since the end of the last ice age," said Donald Grayson, an archaeologist and paleontologist with the University of Washington who has documented the presence of pika over the past 40,000 years.

"Pikas in general are now found at such high elevations that there's not a lot of places left for them," Grayson said.

Imagine the alpine landscape of North America as an ensemble of cones that top out at 3000-4000 meters and it's obvious that range decreases as the minimum elevation rises, and ultimately approaches zero. As in zero pikas.

In the Denver Post's other climate-related story today, the pine beetle infestation I wrote about last summer has crossed the Continental Divide big time and is spreading across the Front Range. The operant hypothesis is that mild winter weather is allowing more beetles to survive into the next season and infest drought-stressed pines. If there's any good news it's that my favorite tree, the ponderosa pine, is more beetle-resistant.

For a birds-eye view of the epidemic, search on "Rand, Colorado" in Google Earth and check out the red-tinged forest to the immediate southwest.