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Factors influencing breeding avifauna abundance and habitat selection in the alpine ecosystem of Colorado

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dc.contributor.authorSpear, Shelley Laine, author
dc.contributor.authorAldridge, Cameron L., advisor
dc.contributor.authorSkagen, Susan K., committee member
dc.contributor.authorDoherty, Paul F., Jr., committee member
dc.date.accessioned2017-09-14T16:05:03Z
dc.date.available2019-09-12T16:04:38Z
dc.date.issued2017
dc.description.abstractSpecies in alpine habitat occupy high elevation areas with limited scope for upslope migration, and as a result are expected to react sensitively to climate-caused habitat alteration. Changes in temperature are causing an advancement of treeline and rearrangement of habitat and species distributions. Alpine birds in particular are predicted to be impacted by climate change, especially species that breed in and are endemic to this ecosystem. In order to understand just how sensitively alpine birds will respond if their habitat structure is altered by climate change, determining the fine-scale mechanisms driving their current relationships with alpine habitat is important. In Chapter 1, I discuss some of the relationships between birds and their surrounding environment and the importance of understanding these species-habitat interactions. I introduce the alpine breeding focal species and how some of these avian species have exhibited population declines in Colorado. I also present my research objectives that aimed to understand breeding avifauna abundance in relation to fine-scale habitat features (Chapter 2), and how specific habitat characteristics drive important breeding site selection for an alpine endemic species (Chapter 3). Chapters 2 and 3 (described below) are data chapters written in a format to be submitted for journal publications. In Chapter 2, I test how fine-scale habitat and environmental characteristics influence abundance of avian species breeding in Colorado's alpine ecosystem. I provide results on how abundance and occurrence of these breeding species were influenced by abiotic, biotic, anthropogenic, temporal, and spatial factors in the alpine. Biotic components affected the abundance of all three of the breeding birds that we modeled using count data; American pipit (Anthus rubescens), horned lark (Eremophila alpestris), and white-crowned sparrow (Zonotrichia leucophrys oriantha). However, abiotic, anthropogenic, spatial and temporal factors also contributed to their abundance and occurrence. Knowing which fine-scale factors influence these alpine species' abundance the most, will allow us to prioritize conservation efforts for each particular species, and improve our ability to predict how their abundance will change if alpine habitat is altered in response to climate change. In Chapter 3, I ask how fine-scale habitat and environmental characteristics influence nest and brood-site selection by breeding white-tailed ptarmigan (Lagopus leucura) in Colorado's alpine. I conducted analyses across multiple spatial scales: patch and site level, at nesting and brood-rearing sites. Forage resources and protective cover were the prominent features driving selection at these two alpine sites during both breeding periods. Specifically, nest site selection at the patch scale was more influenced by percent cover of forage forbs, rock and gravel, and shrubs and willows. However, at the site scale, we found hens selected nest sites when percentage of graminoid cover was less and elevations were lower. Hens selected brood sites at the patch scale that were in closer proximity to willows and shrubs and that had rock and gravel cover to a particular threshold. A subset of our brood data indicated brood site selection was driven by abundance of insects over vegetation components. In this chapter, I highlighted the dependence on forage quantity and protective cover across two ptarmigan breeding stages, as well as differences among scales. These findings demonstrated the importance of considering a spatial resolution with a temporal aspect (i.e., different breeding stages) in resource selection studies especially when habitat covariates are collected at fine spatial scales. With all aspects of this research, I discuss in each chapter how conducting additional and longer-term studies on a fine-scale basis helps to not only establish further alpine breeding bird-habitat relationships in these areas, but in identifying if populations are stable, and if and when they respond to changes in habitat structure. Furthermore, in my final section, Chapter 4, I suggest analyzing these relationships across a larger extent and propose how a landscape-scale analysis can be applied to breeding bird species-habitat relationships in the future to determine at what scale these species could respond if climate change impacts their alpine habitat.
dc.format.mediumborn digital
dc.format.mediummasters theses
dc.identifierSPEAR_colostate_0053N_14310.pdf
dc.identifier.urihttps://hdl.handle.net/10217/183943
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.titleFactors influencing breeding avifauna abundance and habitat selection in the alpine ecosystem of Colorado
dc.typeText
dcterms.embargo.expires2019-09-12
dcterms.embargo.terms2019-09-12
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.)

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