Record Details
Field | Value |
---|---|
Title | Diet and nutrition of female sage grouse during the pre-laying period |
Names |
Barnett, Jenny K.
(creator) Crawford, John A. (advisor) |
Date Issued | 1992-09-04 (iso8601) |
Note | Graduation date: 1993 |
Abstract | Nutrition effects productivity of grouse. Females that obtain high nutrient diets in spring produce larger clutches and larger, more viable chicks than hens on less nutritious diets. Grouse select high nutrient foods to help ensure proper nutrition. Reduced productivity accounted for the decline of sage grouse (Centrocercus urophasianus) populations in Oregon since the 1950s. Summer and fall diets of sage grouse are well described, but no information is available on foraging ecology or diet of hens during the breeding season. The objectives of this study were to determine use, availability, and nutrient content (crude protein, calcium, phosphorus) of key foods of pre-laying female sage grouse. The study was conducted on 2 areas in southeastern Oregon: Hart Mountain National Antelope Refuge and Jackass Creek. Female sage grouse were collected for a 5-week period preceeding incubation (5 March 8 April) 1990-91. Sagebrush (Artemsisa spp.) was the primary food and composed less of the diet in 1990 (55%) than 1991 (80%). The remainder of the diet was composed of forbs. Desert parsley (Lomatium spp.), hawksbeard (Crepis spp.), long-leaf phlox (Phlox longifolia), everlasting (Antennaria spp.), mountain dandelion (Agoseris spp.), clover (Trifolium spp.), and milkvetch (Astragalus spp.) were identified as key forbs. Forbs were used in greater proportion than available, but sagebrush was used less than available. Availability of forbs was lower in 1991 than 1990. Samples of sagebrush from sage grouse crops were higher in crude protein than samples from foraging and random sites, and nutrient content of sagebrush was lower in 1991 than 1990. Forbs were higher in nutrient content than sagebrush. Fewer forbs were eaten in 1991 and crude protein, calcium, and phosphorus contents of the diet were lower in 1991. Productivity of sage grouse on both areas was lower in 1991 than 1990. Results of this study indicate diet and nutrient intake of hens during the pre-laying period may influence productivity of sage grouse. |
Genre | Thesis/Dissertation |
Topic | Sage grouse -- Oregon -- Nutrition |
Identifier | http://hdl.handle.net/1957/35978 |