Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/2/2002
Publication Date: 2/3/2003
Citation: WALD, E.J., KRONBERG, S.L., LARSON, G.E., JOHNSON, W.C. ANALYSIS OF WHOLE SEED PASSAGE IN SHARP-TAILED GROUSE FECES. MEETING ABSTRACT 307. 2003. Interpretive Summary:
Technical Abstract: Birds are well-known seed dispersers and can contribute to the dispersal of many plant taxa including many weedy species. Weed seed dispersal by birds may be a serious problem in some areas. Areas within Theodore Roosevelt National Park (TRNP) in western North Dakota have substantial leafy spurge (Euphorbia esula) infestations. Some of these infestations occur in sharp-tailed grouse (Tympanuchus phasianellus) habitat. This study investigated the possibility of sharp-tailed grouse dispersing leafy spurge. We also identified and quantified seeds of other plant taxa potentially dispersed by sharp-tailed grouse. Grouse feces were collected and analyzed for seed content. Areas for fecal collections within TRNP were selected based on grouse occurrence and leafy spurge infestations. Analysis of 201 sharp-tailed grouse fecal samples indicated that grouse consumed and excreted numerous seeds representing over forty different plant taxa, including leafy spurge. The most frequent taxa recovered were chokecherry (Prunus virginiana), currant (Ribes spp.), buffaloberry (Shepherdia argentea) and tansy mustard (Descurainia spp.), respectively. Feeding trials with captive birds verified that ingested leafy spurge seeds could pass in whole form through the gastrointestinal tract of sharp-tailed grouse. Germination and viability testing showed that some leafy spurge seeds remained viable after passage through sharp-tailed grouse. Although wild grouse are capable of consuming leafy spurge seeds, they showed a preference for fleshy-fruited species during the period when leafy spurge seeds were available.