The U.S. Fish and Wildlife Service wrote this biological opinion to address the cumulative effects of Forest Service activities across the Targhee National Forest's portion of the "Plateau" Bear Management Unit. This area borders Yellowstone National Park to the east, and it the site of the largest timber sale of its time in the lower 48 states, resulting in clearcut logging in the 1960's, 70's, and 80's. The logging and associated roading and high levels of human use had devastating effects on the ability to support grizzly bears, elk, and other wildlife.

The FWS opinion may be a case of "too little, too late" for grizzlies on the Targhee, but it represents a significant "high water mark" for grizzly bear habitat protections regarding logging, road densities, security area designations, etc. If implemented, these standards might allow for restoration of the Targhee in the decades to come.

Vegetative Cover

Lack of vegetative cover may make an area unusable to grizzly bears.

A. Minimum cover standards

The strongest standards yet employed by a government agency to maintain vegetative cover in grizzly bear habitat are on the Targhee National Forest, described in the Forest Service's "Grizzly Bear Management Strategy for the Plateau Bear Management Unit," (hereinafter, "FS Strategy") and the U.S. Fish and Wildlife Service's (FWS') Biological Opinion on the Plateau Bear Management Unit (hereinafter, "FWS Opinion"). Both of these documents incorporate information from a 1987 supplement to the Targhee forest plan, "Endangered, Threatened, and Sensitive Plant and Animal Species and their Habitats on the Targhee Forest" (hereinafter, "TES Supplement"). All three documents contain a minimum cover standard of 50%, including a minimum 20% hiding cover, 20% thermal cover, and an additional 10% hiding or thermal cover. Hiding cover is typically defined as the ability to hide 90% of a grizzly bear at 200 ft. Thermal cover is defined as trees at least 40 feet tall, with a closed canopy of at least 70%. The documents include more detailed definitions.

Cover will not be effective unless it is of sufficient size. The strongest standard currently employed is in the Opinion which states that forested habitats do not constitute hiding cover unless they are at least 4 to 8 sight distances across (4 to 8 times the maximum distance one can spot a bear or other animal). In areas in or adjacent to riparian areas, the minimum standard is 6 to 8 sight distances.

B. Maximum opening size standards (clearcuts)

The strongest standards limiting artificial openings in grizzly bear habitat are found in the three documents cited above (FS Strategy, FWS Opinion, and TES Supplement), and are based on research that indicates that bears typically forage within 150 feet of cover (an circular opening this size will encompass approximately 1.6 acres). The FS Strategy and the FWS Opinion direct that new created openings shall not exceed 1.6 acres in size, and no existing openings greater than 1.6 acres in size shall be enlarged: "Size restriction of new openings ensures there will be no further loss of habitat available to grizzlies for foraging" (FS Strategy, p.58).

Security Areas

In order to provide a sanctuary for grizzly bears temporarily displaced from a timber sale or other development in their habitat, the establishment of grizzly bear "security areas" is recommended. To be effective, security areas should encompass a minimum of 7,000 acres, contain no roads, be devoid of major human activities, and contain seasonal habitat components important to grizzly bears. They should be distributed across a landscape to be able to function as a network, rather than merely isolated "islands" (see FWS Biological Opinion, Plateau BMU, p.31).

Timing Restrictions

Prolonged human activity in an area of grizzly bear habitat may displace bears out of the area such that knowledge and use of that area are no longer passed on to future generations of bears. The area is essentially lost to the population, until or unless grizzly bears relearn how to use the area. For this reason, the FWS has recommended in its biological opinions on various forest plans that the timing of major human activities in grizzly bear habitat be restricted in duration (see FWS Biological Opinion, Gallatin Forest Plan). Current standards governing Management Situation 1 (MS1) lands allow no more than one entry into an area per decade, not to exceed three years in duration. Standards for MS2 lands are not as strong: one entry per decade not to exceed five years in duration (an "entry" is loosely defined as a major human activity, such as a timber sale). The former standard is more defensible biologically, and is the strongest currently employed.

Soil Scarification

Berries are an important food source for bears, particularly in the fall, and in areas where they occur in abundance. Following logging operations, sale areas are typically "scarified," that is, the ground vegetation is mechanically ripped up and turned over to maximize the regeneration of new trees. Berry-producing shrubs are destroyed in the process. In order to preserve berry production in the understory, scarification of the soil must be minimized. The FWS Biological Opinion on the Plateau BMU directs: "In newly harvested units, soil disturbance shall not exceed 20 percent of the unit" (p.35)