Sage-grouse seasonal habitat selection and survival near Jackson, Wyoming

Authors(s): S. Anderson

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Publication Date: 0000-00-00

Type: annual report

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Abstract: Objectives PURPOSE: The purpose of the proposed study is to quantify sage-grouse seasonal habitat selection, the limiting seasonal ranges, and the habitat conditions associated with sustainable productivity. GOAL: The ultimate goal of the project is to provide park managers with sage-grouse habitat selection information that can be used in future pro-active management decisions that lead to healthy sagebrush steppe ecosystems and provide sage-grouse habitat conducive to sustainable populations. PROJECT OBJECTIVES: 1. Identify and vegetatively quantify seasonal habitats used by sage-grouse (including: nesting, brood-rearing, summer, and winter habitat selection). 2. Quantify the immediate effects of management practices and development throughout the park (emphasizing impacts to breeding behavior of airport runway expansion during the 2000 breeding season). 3. Assess the impacts of predation on sage-grouse productivity and seasonal survival. 4. Assess the impacts of ungulate grazing on the sagebrush dominated portions of the park. Findings and Status 18 collared individual hens [21 potential nesting birds (due to 2-year radios)]18/21(86 percent ) initiated nests [7/8 (88 percent ) in 1999; 11/13 (85 percent ) in 2000]9/18 (50 percent ) successfully hatched [4/7 (57 percent ) in 1999; 5/11 (45 percent ) in 2000] All unsuccessful nests predated: 5 suspected raven 4 mammalian (suspected badger) 4/9 (44 percent ) successful through early brood-rearing (chicks lost ?14 days post hatch) 3/4 (75 percent ) in 1999; 1/5 (20 percent ) in 2000 3/4 (75 percent ) successful through late brood-rearing (fledged ?1 chick on August 1) 3/3 (100 percent ) in 1999; 0/1 in 2000 7 chicks fledged (7/21 = 0.33 chicks per potential hen) 19/23 (83 percent ) summer survival (mortalities incurred April 15 through August 1) 8/9 (89 percent ) in 1999; 11/14 (79 percent ) in 2000 6/8 (75 percent ) winter survival (mortalities incurred August 1, 1999 through April 15, 2000) 22 collared individual roosters 23/30 (77 percent ) summer survival (mortalities incurred April 15 through August 1) 14/17 (82 percent ) in 1999; 9/13 (69 percent ) in 2000 10/14 (71 percent ) winter survival (mortalities incurred August 1, 1999 through April 15, 2000). In the Potholes region of GTNP, where shrub canopies and grass cover and heights are significantly lower than the southern reaches of the park, the birds are selecting larger patches (distance to edge measurements) of thicker, taller sagebrush. The forb cover and diversity differences between the 2 areas are primarily due to increased mat forming species (buckwheat spp., phlox spp., etc.) which dominate most of the ground cover within the Potholes. These species are predominantly non-food forb species which provide limited screening cover for nesting grouse. Thus, the birds are selecting nesting habitat based on an increased shrub component. Hens are selecting nesting habitat within the southern reaches of GTNP for sagebrush (live sagebrush canopy measurements) and against the bitterbrush component (no difference in total shrub canopy cover, indicating that sagebrush dominated selected areas, and the difference in the available areas was counteracted by the bitterbrush component). The herbaceous selection hinges around the residual grass and forb elements. Grass heights and cover values surrounding Blacktail Butte are significantly higher than those elsewhere in GTNP, yet the birds are selecting areas with comparatively increased residual grass cover. Regardless of the habitat condition, sage-grouse are selecting habitat based on the sagebrush element within the park. Therefore, pro-active management decisions, specifically, burning of sagebrush dominated areas, need to be well planned to ensure that adequate sagebrush cover remains following the treatment. For a full discussion, consult 2000 Annual report submitted to GTNP.

Keywords: animal, bird, ornithology, Aves, sage grouse, grouse, habitat, population, breeding, mortality, Centrocercus uraphasianus, Jackson Hole, Teton County, management, human activity, predation, ungulate, radio collar, nest, nesting, habitat, raven, Corvus corax, Corvidae, badger, Mustelidae Taxidae taxus, Grand Teton National Park