Colt Summit: Researcher on Seeley Lake’s lynx and forest management
We’ve obviously had a number of in-depth discussions and debates about the Lolo National Forests’s Colt Summit timber sale in the Seeley-Swan Valley of western Montana. However, something just arrived in my in-box this morning, which I thought would be good to highlight here for further discussion.
It’s a 2009 letter from John R. Squires , Research Wildlife Biologist at the Rocky Mountain Research Station in Missoula in response to specific questions from a rural landscape scientist with Missoula County’s Rural Initiatives program. The subject of the letter is lynx, and specifically lynx in the Seeley Lake area of western Montana. As frequent readers of this blog will recall, Missoula County joined with The Wilderness Society, Pyramid Mountain Lumber, National Wildlife Federal, Montana Wilderness Association, Montana Wood Products Association, Montana Logging Association and others to file an amici brief in full and unequivocal support of the Forest Service’s Colt Summit timber sale.
However, despite the enthusiastic support of these collaborators, a federal district court judge issued the following ruling:
Summary judgment is granted in favor of the plaintiffs on their claim that the defendants violated NEPA by failing to adequately analyze the Colt Summit Project’s cumulative effects on lynx….
IT IS FURTHER ORDERED that this matter is REMANDED to the Forest Service so that it may prepare a supplemental environmental assessment consistent with this order and the law.
IT IS FURTHER ORDERED that the defendants are enjoined from implementing the Colt Summit Project while the proceedings required on remand are pending.
Squires 2009 letter provides some more information regarding lynx in general, but also specifically about lynx in the Seeley Lake area and how these lynx – and their habitat – are impacted by forest management practices such as logging and “thinning.” Of particular interest is that Squires states that “The Seeley Lake area represents some of the most important lynx habitat in Montana.” And also, “[L]ynx are very sensitive to forest management, especially forest thinning. Thinning reduces habitat quality for lynx with effects lasting up to several decades.”
Finally, there’s this tidbit of information from Squires, “[T]here is likely a threshold of thinning below which lynx will not be able to persist. The extent of forest thinning and forest fragmentation around Seeley in the last 5 years is of concern for lynx in western Montana. Preliminary analysis of population viability suggest that lynx in the Seeley area may be declining, so concerns for maintaining available habitat does have a scientific basis.”
Below are some excerpts from Squires letter (please note that the added emphasis is mine):
We have studied lynx in western Montana for a decade and my answers are based on our understanding gained during this research. I will focus my comments on our scientific understanding realizing that results from this research may have policy implications. You asked the following questions:
1) What information can you provide about the importance of the Seeley Lake area to lynx, especially in regards to the Northern Rockies?
Since the federal listing of Canada lynx in 2000, it has become clear that Canada lynx have a very limited distribution in the contiguous United States. Other than Montana, native populations are only found in Washington, Maine, and small populations in Minnesota and Wyoming that may consist of only a few individuals. Lynx in western Montana represents possibly the most viable native population in the contiguous United States and it is a primary focus of conservation planning for the species….The Seeley Lake area represents some of the most important lynx habitat in Montana. The areas surrounding Seeley Lake are not only central to the conservation and management of Canada lynx in western Montana, but also to the management of the species in the contiguous United States.
Lynx avoid low elevation, dry forest types and the open high elevation tundra habitats. Lynx are restricted to high elevation, spruce-fir forests, like those found around Seeley Lake. We compared habitat characteristics found in 59 lynx home ranges to 500 random areas of similar size. We found that lynx preferentially select home ranges with low topographic roughness; they generally avoid the very steep topographies like the central portions of Glacier National Park and parts of the Bob Marshall Complex. Instead, lynx preferentially select spruce-fir forests found in more rolling topographies, like those found in Seeley Lake and in the Purcell Mountains north of Libby, MT. These boreal landscapes are rare in western Montana and they are the landscapes most impacted by forest management. The spruce-fir forests that surround Seeley Lake are readily used by lynx (Figure 1). The future management of these forests will be important to the species’ recovery.
2) How have lynx persisted in Seeley Lake despite extensive timber harvesting and recreation?
Based on 10 years of research in western Montana, we recognize that lynx occupy a very narrow habitat niche due to their highly-specialized, morphological adaptations for hunting snowshoe hares in deep-snow. During winter, lynx hunt preferentially in mature, multi-layer, spruce-fir forests. In summer, lynx remain in their same home ranges, but they broaden their niche to also include young regenerating forests that contain dense horizontal cover. Lynx are almost completely dependent on snowshoe hares (96% winter food biomass) for food, and the abundance of hares is directly rated to the amount of horizontal cover provided by forests vegetation. Therefore, lynx are very sensitive to forest management, especially forest thinning. Thinning reduces habitat quality for lynx with effects lasting up to several decades.
Although lynx are sensitive to forest management, they do persist in the Seeley Lake area and other managed landscapes, provided that a mosaic of suitable habitat is available, including a high abundance of un-thinning forests. Landscapes that offer a mosaic of forest age and structure classes provide habitat for denning and foraging. Although substantial forest thinning has occurred in the Seeley Lake area, lynx have been able to use un-thinned habitats. However, there is likely a threshold of thinning below which lynx will not be able to persist. The extent of forest thinning and forest fragmentation around Seeley in the last 5 years is of concern for lynx in western Montana. Preliminary analysis of population viability suggest that lynx in the Seeley area may be declining, so concerns for maintaining available habitat does have a scientific basis.