Two new studies on the issue have been published

Apr 28, 2010 18:01 GMT  ·  By

According to the United States Geological Survey (USGS), the Greater Yellowstone and Northern Continental Divide ecosystems are the two strongest habitats for grizzly bears in the country. Working in these areas, the investigators of the federal agency sought to determine the perils and threats ungulates are exposed to, as well as to identify some of the most harmful factors affecting their chances of survival. Two new studies show that human development is directly responsible for more bears dying, and also that new bear rub tree surveys can be efficient on keeping tabs on existing grizzly populations.

Published in the latest issue of the esteemed scientific Journal of Wildlife Management, the studies detail some of the most suitable dynamic tools that could be used by wildlife experts in devising conservation and management programs aimed at these animals. The two papers also identify additional threat factors for the bears, besides roads and developed areas. The latter two have already been found to be significant threats in previous investigations. The new conclusions are based on no less than 21 years of grizzly bear tracking information, USGS experts say.

During the research, it was established that areas of the two ecosystems subjected to rural home development also pose a significant risk level for bears, especially those under the age of 2. Needless to say, regions where bear-hunting is allowed in the fall also show reduced numbers of bears than wilder regions, where the animals have little to no contact with humans. “Our research shows that bears living in areas with human development and activity including roads, campgrounds, lodges, and homes have a greater chance of dying than bears living in more remote and secure areas,” explains Chuck Schwartz, a wildlife biologist at the USGS and the leader of the Interagency Grizzly Bear Study Team.

The papers also indicate that studying traces bears leave behind while rubbing against trees at night might be a solid tool in assessing the health of grizzly bear populations. “This type of information is valuable to land managers when planning for resource development, recreational activities, and road building or removal throughout the region,” Schwartz believes. “These methods could potentially be used for other species that are difficult to study because they live in remote and rugged areas. They could also provide a reliable estimate of population trend and be more affordable and safer than collaring bears,” concludes USGS biologist Katherine Kendall, the leader of the Northern Divide Grizzly Bear Program.