Repository logo
 

Impacts of elk management and riparian condition on songbirds in Rocky Mountain National Park

Simple item page
dc.contributor.authorCraig, Apryle Dawn, author
dc.contributor.authorPejchar, Liba, advisor
dc.contributor.authorAldridge, Cameron, committee member
dc.contributor.authorNoon, Barry, committee member
dc.contributor.authorBobowski, Ben, committee member
dc.date.accessioned2015-08-27T03:57:19Z
dc.date.available2015-08-27T03:57:19Z
dc.date.issued2015
dc.description.abstractThe widespread loss of apex predators from the western U.S. is having cascading effects on ecosystems. As in other western parks, riparian willow (Salix spp.) communities in Rocky Mountain National Park (RMNP) are declining as a result of a trophic cascade involving the local extinction of wolves (Canis lupus) and an exponential increase in elk (Cervus elaphus). In 2008, RMNP began installing elk exclosures to protect and restore willow communities and the diverse taxa that depend on riparian ecosystems from heavy browsing. Using point counts, I evaluated the effect of elk exclosures and riparian shrub condition on songbird density and occupancy. I found little support for a direct effect of elk exclosures on bird communities, with the exception of shrub nesting birds which occurred at higher densities within exclosures. However, the density and occupancy of some riparian bird species and guilds was positively correlated with particular vegetation conditions in this ecosystem. Shrub height positively related to both density and occupancy of Dusky Flycatcher. For the Lincoln Sparrow and shrub-nesting guild, occupancy also had a positive relationship with shrub height. The percent of shrub cover within 15 m of the survey point was an important positive predictor of density for Lincoln's Sparrows, Song Sparrows, and Wilson's Warblers, and foliage-gleaner and shrub-nesting guilds. The percent of riparian shrub cover within 300 m was an important positive predictor for the density of Wilson's Warblers. American Robin, a habitat generalist, and ground-nesting and foraging guilds did not respond strongly to shrub cover or height at any scale. These results reflect the variable shrub conditions inside and outside exclosures, and affirm that managing for mid to high density shrub cover and height will be beneficial for some riparian specialists. My findings provide park managers critical information on bird communities in experimental elk exclosures, and insight into the conditions needed to support songbird communities in the park's riparian ecosystems.
dc.format.mediumborn digital
dc.format.mediummasters theses
dc.identifierCraig_colostate_0053N_12960.pdf
dc.identifier.urihttp://hdl.handle.net/10217/166994
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado State University. Libraries
dc.relation.ispartof2000-2019
dc.rightsCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.
dc.subjectexclosures
dc.subjectriparian buffer
dc.subjectwillow
dc.subjectherbivory
dc.subjectbirds
dc.subjecttrophic cascades
dc.titleImpacts of elk management and riparian condition on songbirds in Rocky Mountain National Park
dc.typeText
dcterms.rights.dplaThis Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
thesis.degree.disciplineEcology
thesis.degree.grantorColorado State University
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (M.S.)

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Craig_colostate_0053N_12960.pdf
Size:
995.55 KB
Format:
Adobe Portable Document Format
Download

Collections

2000-2019
Theses and Dissertations