However, if there are established populations of females, such as there are up here in the Northern Continental Divide ecosystem and down here in Yellowstone, males may be able to move back and forth. Male dispersers are efficient agents of gene flow. The male portion of the population maintains genetic diversity over large areas. That's why all the Arctic bear populations are somewhat similar genetically, because of males traveling back and forth between demes of females. That's why there's hope for a regional metapopulation of Grizzly Bears in the Rockies: if there are females that live in the core areas and males can travel between those areas and maintain genetic diversity. The question is, will males be able to travel between those areas?

So to answer that question or to understand it better, we looked at other, smaller patches of habitat between those core areas, which we called regional nodes, or maybe sub-populations. These areas, which are outlined in green, are primarily roadless areas of good bear habitat. These may serve as stepping stones for Grizzly Bears to travel across - not only Grizzly Bears but Martens and Lynx and Fisher and Mountain Lions. As I mentioned, several of these areas have had bears living there in the past such as over here in the Tobacco Root Mountains and the Big Belts.

We used this same Least Cost Path analysis between each of these smaller patches and we came up with this regional map; sort of a regional reserve matrix with core areas and corridors. This is kind of the first rough map of what a regional metapopulation of Grizzly Bears might look like. The purple areas are core habitat that could support bears. These are areas where human activities should be compatible with bear security. The colored pathways are potential corridors. The brighter colors, red and yellow, indicate better connectivity between them. These are areas where animals may be able to travel.

The bears that showed up out here in the Tobacco Roots obviously, probably, came from Yellowstone. So they traveled across some of these corridors. There's other evidence that these potential corridors have been used by other species, mountain lions and elk and other things. But human development, in most cases, is a barrier to animal dispersal.

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