Record Details
Field | Value |
---|---|
Title | Response of brood-rearing habitat of sage grouse to prescribed burning in Oregon |
Names |
Pyle, William H. (William Hanson), 1957-
(creator) Crawford, John A. (advisor) |
Date Issued | 1992-11-13 (iso8601) |
Note | Graduation date: 1993 |
Abstract | Decline of western sage grouse (Centrocercus urophasianus phaios) in Oregon may be related to the reduced availability of foods in upland sagebrush (Artemisia)-grasslands used for brood-rearing. The goal of this study was to determine primary foods of chicks and the short-term response of brood-rearing habitat to prescribed burning at Hart Mountain, Oregon. Analysis revealed that food use by 44 chicks and availability at collection locations differed (P > 0.001) among forb and insect taxa. Eleven forb and insect genera were used selectively (primary foods) and collectively composed 58% of the diet by aggregate mass. Primary foods included Cichorieae (Crepis sp., Agoseris spp., Taraxacum sp.), milkvetches (Astraqalus spp.), microsteris (Microsteris sp.), desertparsley (Lomatium spp.) and ground-dwelling beetles (Scarabaeidae, Tenebrionidae). Compared with 1-5 week-old chicks, 6-10 week-old chicks consumed less (P < 0.05) annual forbs (36 and 14%) and ground-dwelling insects (32 and 16%) but more perennial forbs (30 and 55%) and sagebrush (2 and 16%) by aggregate mass. Response of brood-rearing habitat to prescribed burning was evaluated in sagebrush-bitterbrush (Purshia tridentata) communities with a randomized block design established in stands where shrub cover exceeded 35%. Within blocks, habitat response was evaluated for 2 growing seasons on 4 plots used as controls, 3 plots burned in November 1987, and 4 plots burned in March 1988. Fall burning increased (P < 0.05) frequency of Cichorieae. Other primary foods, including microsteris, desert-parsley, and ground-dwelling beetles, were not influenced by burning. Additionally, spring and fall burning reduced shrub cover and increased total forb cover and diversity, but grasses and insect orders were not substantially influenced. Although prescribed burning increased habitat heterogeneity, its utility may be limited as a food enhancement practice. Primary forbs and insects responded inconsistently and sagebrush, which serves as both food and cover, responded negatively. Evaluation of brood-rearing habitat should be based on several criteria including an understanding of the interaction between land-use practices and availability of primary foods of chicks. |
Genre | Thesis/Dissertation |
Topic | Sage grouse -- Oregon -- Habitat |
Identifier | http://hdl.handle.net/1957/23060 |