2008-02-04_PERMIT FILE - C1982056A

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dominant shrub in sagebrush/meadow is' silver sagebrush, while in low sagebrush and mountain sagebrush the • dominant shrub is low sagebrush and big sagebrush, respectively. Common understory species in mountain and low sagebrush are big bluegrass, slender wheatgrass, mulesears wyethia, yarrow and lupine. In sagebrush/meadow, Kentucky bluegrass, Baltic rush, sedges, yarrow, Canada thistle (Cirsium arvense), and new Mexican checkermallow (Sidalcea neomexicana) are predominant understory species. In quantitative sampling conducted for the vegetation information presented in [his permit application (see Rule 2.04.10 Response), forb production and percent cover in the low and mountain sagebrush types (combined) were 22.6 g/m2 and 16.8 percent, respectively. Forb production and percent cover in sagebrush/meadow were 37.9 g/m2 and 14.9 percent, respectively. Qualitative observations in the low and mountain sagebrush communities indicated [hat in areas where sagebrush canopy cover approached ~0 percent, understory forbs and grasses were considerably reduced. Based on previous studies and qualitative observations and quantitative measurements of sagebrush communities in [he permit area, certain assumptions can be made regarding sage grouse utilization of these communities. Open areas of low sagebrush are potentially important as breeding grounds. Sagebrush canopy measured on [he Twentymile Lek was 10.2 percent, the lowest value obtained in the low sagebrush community. Nearly all researchers have reported that sage grouse prefer open areas surrounded by low sagebrush as strutting grounds (Patterson 1952, Rodgers 1694, Gill 1965, Wallestad 1975), although there is some use of other open areas such as hay meadows (Rodgers 1964). Open, low sagebrush areas are also preferred by broods for feeding on insects and forbs. Initially sage grouse chicks arc heavily dependent on insects, but as they grow older (by 12 weeks of age) their diet is dwninated by forbs (Klebenavv and Gray 1968, Peterson 1970). Habitats utilized by broods shift from low sagebrush to meadows and back to sagebrush as summer progresses (Gill 1965, Wallestad 1971). Broods have also been shown • to move up in elevation as the summer progresses and as green food plants dry up a[ the lower elevations (Klebenow 1969). Wallestad (1971) and Martin (1970) found that the majority of broods located in early summer were in areas with average sagebrush canopy coverage of 14 percent. Martin's (1970) studies also showed that juveniles preferred sites with short sagebrush while adults preferred areas of tall sagebrush. Forb cover in low and mountain sagebrush communities on the permit area was lower than that found for preferred brood feeding sites in other studies. In studies by Peterson (1970), average forb cover was measured at 33 percent in brood feeding areas. Reduced availability of forbs in sagebrush in [he permit area may be compensated for by grouse feeding in cropland, reclaimed pastureland, and fallow fields on [he permit area. Several opportunistic observations of grouse were made itt cropland habitat during the 1984 field studies. Dandelion (Taraxacum officinale), a preferred food of juvenile grouse (Peterson 1970), appeared to be fairly abundant in fallow fields. In addition, many grouse have been observed on reclaimed pastureland during the fall hutting seasons (1980-83). Forbs such as lactuca (Lactuca serriola) and yellow sweet clover (Melilotus officinalius) that are abundant on some of the newly reclaimed pastureland were [he predominant food found in [he crops of harvested birds. Stands of mountain (big) sagebrush, particularly those in close proximity to leks, provide suitable nesting habitat. Studies by Wallestad and Pyrah (1974) in Montana showed that 68 percent of all nests located occurred within 2.4 km (I.5 mi) of the lek. Studies by Authenrie[h (1976, as cited in Braun et al. 1977) in Idaho indicated that distance of nests from leks varied depending on the proximity of the lek to quality nesting habitat. In his studies 85.0 percent of [he nests were within 6.4 km (4.0 mi) of dte lek, 97.2 percent were within 9.7 km (6.0 mi), and all nests found were within 12.5 km (7.8 mi) of a lek. Patterson (1952) and Gill (1965) found that 92 percent of the nests • located occurred under sagebrush plants. All [he nests located b}' Wallestad and Pyrah (1974) occurred beneath sagebrush plants. Sagebrush communities used for nesting are characterized as ranging between 17 and 79 cm (6.7-31.1 in) in height (with nests usually under the tallest bushes available) and exhibiting a canopy cover of 20 to 40 percent (Patterson 192, Klebenow 1969), Wallestad and Pyrah 1974, Petersen 1980). In addition, Wallestad A4R 97-I>4 2.04-72 Revised 10/02/97