Monday, February 23, 2009

Pack Rats

Thump, thump, thump, thump: Throughout the night on Saturday, I was awakened by the sound of a critter running around the walls and ceilings. I was staying at a cabin in the Boise National Forest near Lowman, and it was easy to figure out the culprit: the bushy-tailed woodrat.

Woodrats are more commonly known as pack rats, and while they're quite common, you might not know they're around until one wakes you up in a forest cabin.

Pack rats figure prominently in Western lore. Prospectors found out the pack rat's love of shiny object the hard way, as gold nuggets, coins and belt buckles disappeared. The pack rat reportedly will drop food for the chance to gather shiny objects--what biologists call "trading."

Pack rats don't hibernate. They store enough food in caches to get them through the winter.

They also collect debris into large piles called middens. The middens serve nests to protect them from predators. They can be used by generation after generation of wood rat--becoming as high as ten feet tall.

Pack rat urinate on their middens; in a protected area, this urine solidifies over time, becoming hard and crystallized. As such, they can remain preserved for 40,000 years or longer.

Due to the pack rat's collecting habits, it's hard to predict what might turn up in a midden. Some sources report items like diamond rings, guns and even a human skull.

More importantly, ancient middens of tremendous value for paleontolists, climatologists and conservationists. Researchers can determine how plant composition of an area has changed over time. The presence of animal bones and dung can help determine population densities of Pleistocene fauna. As such, they can help track climate change, species declines and extinctions and long-term habitat trends. --Matt Miller

4 comments:

Anonymous said...

I have trapped a wood rat that looks like the one you pictured in the article. I live off Highway 21 close to Idaho City. The dilemma is that I am being told the one you pictured is not a bushy tailed wood rat which leaves in question what habitat needs to be located before it can be released. Can you help me with this question.

TNC-Idaho said...

There are only 2 kinds of wood rats in Idaho, the bushy-tailed and desert. Around Idaho City, it's likely a bushy-tailed. In any case, both species are pretty adaptable. Releasing it near an area with a lot of boulders, rocks or canyons would be fine. Good luck.

Anonymous said...

I live at 4200 ft elevation near Cottonwood, ID. My dog has brought home 8 or 10 of these bushy-tailed wood rats just this spring. Never had seen them before this year.

Anonymous said...

I live at 4200 ft elevation near Cottonwood, ID. My dog has brought home 8 or 10 of these bushy-tailed wood rats just this spring. Never had seen them before this year.