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Glasgow Field Trip

Glasgow Field Trip Notes

June 16, 2004

Anne Cossitt welcomed the group and summarized the purpose of the field trip, which was to identify seasonal sage grouse habitats and assess and discuss habitat conditions. Cossitt handed out copies of Appendix B of the state sage grouse plan, which contains habitat assessment worksheets. Cossitt introduced John Carlson, BLM biologist, and Pat Gunderson, FWP biologist, who organized the field trip and would lead the group.

Field Trip Location

The field trip took place on lands in the Brazil Creek drainage southwest of Glasgow, Montana.


Photo 1: Transmission line

Stop 1: Lek Area

The first stop on the field trip was conducted along the road at a point where a large power transmission line crossed the landscape. Biologists John Carlson and Pat Gunderson pointed out some causes of habitat fragmentation and other issues associated with sage grouse productivity. The power lines (see photo 1 below) create perching locations for raptors in an area otherwise devoid of such perches. Roads leading to the power lines (and roads in general) also fragment the habitat. Pat pointed out that this is an issue in coalbed methane (cbm) development (projected for southeastern Montana) because roads will be needed to develop the wells, distribute the gas, and provide power lines. Generally, fragmentation from roads and power lines is not an issue in the Glasgow area.


Photo 2: Pond and cropland near horizon on left side of photo

The site has wet areas (note the water development in left side of photo 2), which can translate into good late-season brood-rearing habitat (for feeding on forbs and insects), but also contains some lands that have been converted to farm land and no longer provide sage brush habitat. A participant noted that the birds do feed in the crop fields. Others pointed out that the birds cannot digest grain, so the birds are likely feeding on insects in the field. The amount of cropland in this landscape (see photo 2, left side, to the left and "below" the pond area) is not a huge negative factor for sage grouse, but at one time much of the area now converted to cropland (from the Milk River to this stop) was likely sage grouse habitat.

Stop 2: Breeding Habitat Area (in Brazil Creek drainage)

At the next stop, the group reviewed in detail the methodology used to assess habitat condition for a breeding site. John Carlson indicated that the Brazil Creek area is known to be a good location for sage grouse, with good population numbers.

Steve Klessens, who for the past two years has coordinated habitat assessments on dozens of sites using the "Sage Grouse Habitat Assessment Worksheet-Breeding Habitat" forms in Appendix B of the state plan, walked the group through the process.

He said that people who assess habitat start by looking at sites with sagebrush within one mile of a lek. The site that was examined as part of this field trip is similar to many sites that assessors examine in locations where lek populations are strong and healthy.

sagegrouse3 Photo 3: 100-foot line measure

The first step is to generally identify a representative location. "Until you've done this for a while, it will seem that the sagebrush is always thicker just beyond where you're at, but when you get there, you find it's the same," stated Klessens. It's a matter of looking at the sagbrush obliquely rather than straight down.

The next step is to determine direction to take a 100-foot sample line. This is done by having someone randomly call "time," then look at a watch for the direction of the second hand. The line goes in that direction (unless that direction takes off toward mostly hardpan or bare ground where every other direction pretty much has sagebrush). "There is some element of subjectivity in the assessment," stated Klessens. Once direction is determined, the 100-foot line is set and the end point also located with GPS.

The following is a summary of results and discussion that occurred during the assessment.

  • Cover type: Not discussed.
  • Average big sagebrush canopy cover: The exact locations of big sagebrush canopy were noted along the 100-foot line (see photo 3, below). The average canopy cover was 9.7%, which would place this right at the borderline between "unsuitable" and "marginal" habitat.
  • Average big sagebrush height: Average height was less than 10 inches, placing this area in the " unsuitable" habitat range. (See photo 3 for indication of sage brush height).
  • Big sagebrush growth form: Not discussed.
  • Average herbaceous grass and forb height: Klessens showed the group how to assess average grass height. A "Daubenmire" frame is placed every five feet along the 100-foot line (see photo 4, below). The grass measurement should be this year's grass (not residual grasses from past years). Take the measurement of the tallest grass within a 1.5-foot half- circle (centered along the Daubenmire's center point on the 100-foot measurement line). This is done for every Daubenmire frame placement, and then the average is calculated, so the result is actually the average of the tallest grass measured in each frame. The Daubenmire frame was situated only once, so no average along the 100-foot line was calculated. The tallest grass in the one frame was measured at 7 inches.
  • There was considerable discussion in the group about the title of this category. There were no forbs on the site yet, although some may emerge in a few weeks. Also grass is grass—isn't it always herbaceous?
  • Average grass canopy cover and Average forb canopy cover: This is assessed using the Daubenmire frame. No estimate was made for canopy cover.

Overall Site Evaluation: This site would rank as unsuitable or marginal using the forms and protocol for habitat assessment in Appendix B.

General Observations


Photo 4: Daubenmire frame

There are serious questions about the effectiveness of the habitat assessment forms for assessing habitat in northeastern Montana. The site was in an area known to be one of the best sage grouse areas (in terms of actual counts) in the Glasgow area, so it must be meeting sage grouse needs, but it ranked as unsuitable in many categories on the habitat condition assessment forms. Folks noted that the forms had been developed based on sage grouse habitat work in the Great Basin, where type, height, and density of sage brush, other vegetative types, and soil conditions are considerably different from northeastern Montana.

Randy Matchett, of the Charles M. Russell National Wildlife Refuge, indicated that Brendan Moynihan and other Ph.D. students were working on studies to better understand the relationship between habitat conditions in northeast Montana and sage grouse populations. The first report should be available in about a year.

Other comments indicated that perhaps the assessment forms would produce more favorable results if the measurements were for smaller areas, just right around the area where the birds might nest. It was pointed out, for example, that on a small nearby knob, the sagebrush was much higher and denser, but it didn't extend for a 100-foot length. The area may have measured only 10-foot square. Perhaps it would be important to note frequency of these areas within the larger landscape.


Leo Barthelmess
Don Burke
Chuck Carlson
John Carlson
Paul Cornwell
Anne Cossitt
Diane Dirkson
Randy Dirkson
Dan Gerike
Pat Gunderson
Steve Henry
Steve Klessens
Maxine Korman
Randy Matchett
Larry Murphy
Darell Olson
Dave Pippin
Rick Stellflug