Sunday, May 03, 2009

Expanding wildlife ranges

Since I've been hiking, some wildlife species have expanded their ranges; more have retracted or become far less common throughout their range. I wish all range expansion was of native animals to the region but some non-native North American animals have been introduced for hunting.

The most publicized example is the reintroduction of wolves to the Yellowstone area and Idaho. I've seen Yellowstone wolves while hiking several times and heard wolves and seen tracks in the Lolo Pass area of Idaho. I'm pleased with the spread of wolves in the west although I'm aware that not everyone is so pleased especially local ranchers. I graduated with a degree in biology from Idaho State University in Pocatello and remember persistent rumors of wolves in the Yellowstone area when I was there 35 years ago. In one case I heard directly from the participants who were biology graduate students. They had gone cross-country skiing in Yellowstone and saw what they thought was a wolf. In the same area they found tracks in snow larger than coyote tracks. Of course other animals than a wild wolf could have made these tracks. A pet wolf or dog or escaped wolf/dog/coyote mix could have made these tracks. And, the tracks may have been enlarged by melting and/or made by a very large coyote. It is certain that even if wolves did move through the area after local extirpation, they did not establish a permanent breeding population before reintroduction. Still it is pleasant to think some wolves may have added their genes to the packs without human intervention.

Speaking of Yellowstone Park, mountain goats can now often be seen in the northeast area on and around Mt. Barronette. Mountain goats were introduced to the Absaroka and Gallatin mountains in the past, they are not native to the Yellowstone area. I hope they do not cause the same problems as the introduced mountain goats have caused in the Olympic Mountains, particularly destruction of alpine vegetation.

On my recent trip to the Methow area, I saw turkeys along the road a few times. These are also non-native animals, introduced for hunting. I'm not aware of any problems yet from turkey introductions but I know non-native introductions of other species have caused serious problems including extinction of native populations.

Growing up in north Idaho, I do not remember seeing Stellar's blue jays in local rural areas. Sometime in the 1980s Stellar's blue jays expanded into the small towns and rural areas. I know Stellar's blue jays were in north Idaho before then, the Lewis and Clark expedition clearly describes them. Did they expand their range into areas near people or did they move back into areas they had previously lived in but were pushed out?