Graduate Theses, Dissertations, and Problem Reports 2018 ECOLOGY AND MANAGEMENT OF GOLDEN-WINGED WARBLERS (VERMIVORA CHRYSOPTERA) AND ASSOCIATED AVIAN SPECIES IN THE ALLEGHENY MOUNTAINS OF WEST VIRGINIA Kyle R. Aldinger Follow this and additional works at: https://researchrepository.wvu.edu/etd Recommended Citation Aldinger, Kyle R., "ECOLOGY AND MANAGEMENT OF GOLDEN-WINGED WARBLERS (VERMIVORA CHRYSOPTERA) AND ASSOCIATED AVIAN SPECIES IN THE ALLEGHENY MOUNTAINS OF WEST VIRGINIA" (2018). Graduate Theses, Dissertations, and Problem Reports. 7152. https://researchrepository.wvu.edu/etd/7152 This Dissertation is protected by copyright and/or related rights. It has been brought to you by the The Research Repository @ WVU with permission from the rights-holder(s). You are free to use this Dissertation in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you must obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This Dissertation has been accepted for inclusion in WVU Graduate Theses, Dissertations, and Problem Reports collection by an authorized administrator of The Research Repository @ WVU. For more information, please contact [email protected]. ECOLOGY AND MANAGEMENT OF GOLDEN-WINGED WARBLERS (VERMIVORA CHRYSOPTERA) AND ASSOCIATED AVIAN SPECIES IN THE ALLEGHENY MOUNTAINS OF WEST VIRGINIA Kyle R. Aldinger Dissertation submitted to the Davis College of Agriculture, Natural Resources, and Design at West Virginia University in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Forest Resource Science Petra B. Wood, Ph.D., Chair James T. Anderson, Ph.D. Catherine M. Johnson, Ph.D. George T. Merovich, Ph.D. Michael P. Strager, Ph.D. Wildlife and Fisheries Resources Program, Division of Forestry and Natural Resources Morgantown, West Virginia 2018 Keywords: breeding season, cattle, community, conservation, density, dispersal, disturbance, elevation, forest, grazing, habitat, nest, pasture, population, shrub, spatial, succession, survival Copyright 2018 Kyle R. Aldinger ABSTRACT ECOLOGY AND MANAGEMENT OF GOLDEN-WINGED WARBLERS (VERMIVORA CHRYSOPTERA) AND ASSOCIATED AVIAN SPECIES IN THE ALLEGHENY MOUNTAINS OF WEST VIRGINIA Kyle R. Aldinger This dissertation focuses on the breeding season ecology and management of Golden- winged Warblers (Vermivora chrysoptera) in the Allegheny Mountains of West Virginia with implications for other disturbance-dependent avian species. Golden-winged Warblers have a complex life history, requiring dynamic forest landscapes with varying age classes for breeding. Populations breeding in the Appalachian Mountains are among the most rapidly decreasing among vertebrates in eastern North America. For these reasons, much research already has been completed on Golden-winged Warblers. Nonetheless, we still have a limited understanding of the causes of population decreases and these causes may vary regionally. I organized this dissertation into 3 parts (Part 1: Introduction, Part 2: Golden-winged Warbler Ecology, Part 3: Golden-winged Warbler Management) including 6 chapters that follow a progression of accumulating knowledge on Golden-winged Warbler population decreases in the Allegheny Mountains of West Virginia. Part 1 includes chapter 1 and is an introduction to the dissertation. In chapter 1, I provided a brief introduction and justification for my research, placed the dissertation into the context of ongoing Golden-winged Warbler research across the species’ range, and outlined the dissertation content. Through impressive collaborative efforts, our understanding of Golden- winged Warbler ecology and management grew substantially during 2008–2016, the period during which this research took place. Part 2 includes chapters 2–4 and focuses on Golden-winged Warbler ecology with an overall objective of filling knowledge gaps for the species to enhance conservation efforts and inform future research. In chapter 2, I evaluated variables at multiple spatial scales during 2008– 2015 to identify conditions that supported high densities of breeding Golden-winged Warblers and associated avian species. Spatial scales used for analyses represented annual dispersal (5-km radius), extra-territorial movement (1.5-km radius), intra-territorial movement (100-m radius), and local resource utilization (11.3-m radius). Golden-winged Warbler density peaked when the minimum elevation was 804 m at the 1.5-km radius scale but was negatively associated with 100-m radius minimum elevation. Density was positively associated with 100-m radius shrubland cover. I identified White-eyed Vireo (Vireo griseus), Blue-gray Gnatcatcher (Polioptila caerulea), Gray Catbird (Dumetella carolinensis), Brown Thrasher (Toxostoma rufum), and Yellow Warbler (Setophaga petechia) as species most likely to benefit from management for Golden-winged Warblers. Golden-winged Warblers ordinated higher along the 100-m shrubland cover gradient than any other bird species, suggesting they may be the most shrubland area-sensitive songbird in my study area. However, the species also requires heavily forested landscapes. Therefore, a species-specific conservation strategy that balances shrubland (patches 9–13 ha comprising 15% of the landscape) and contiguous forest area (≥75% of the landscape) could concurrently meet the needs of Golden-winged Warblers and many other avian species. In chapter 3, I used a spatial Cormack-Jolly-Seber (s-CJS) model to obtain minimally- biased estimates of annual survival and breeding and natal dispersal for Golden-winged Warblers during 2008–2015, as well as for locally less abundant Blue-winged Warblers (V. cyanoptera) and their hybrids. Vermivora warbler annual survival did not vary by phenotype, sex, or study area, but adult annual survival (0.53, 95% confidence interval [CI] = 0.46–0.60) was higher than juvenile annual survival (0.09, 0.05–0.13). Adjusting for mortality during the post-fledging period, juvenile annual survival may be about half of adult annual survival. Expected breeding dispersal (329 m, 316–344 m) was less than expected natal dispersal (544 m, 500–592 m) based on our s-CJS model. I observed the longest distances for natal dispersal (mean = 1,587 m, median = 1,047 m, n = 18), intermediate distances for second year to after second year dispersal (mean = 492 m, median = 132 m, n = 46), and the shortest distances for after second year dispersal (mean ± SE = 290 m, median = 103 m, n = 103). Female (716 ± 162 m, n = 43) warblers tended to disperse farther than males (404 ± 64 m, n = 124). These results provide the first estimates of annual survival that account for permanent emigration and have important implications for conservation network design given our estimates of dispersal. In chapter 4, I investigated the spatial configuration of shrubs within Golden-winged Warbler breeding territories using a combination of field-measured and light detection and ranging (LIDAR) vegetation data during 2011–2014. Golden-winged Warblers selected nest sites with more shrub cover (mean ± SE = 49.3 ± 2.3%) than random locations (mean ± SE = 42.9 ± 2.9%) but did not select for a particular shrub community configuration for nesting. The species selected territories with more pronounced edges (≥60% difference in shrub cover on either side of a given point) and a more clumped rather than dispersed or uniform shrub configuration (shrub clumps 4.6–22.6 m wide) than would be expected given a random configuration of shrubs, although selection was relatively weak. Selection for pronounced edges between shrub and non-shrub cover and clumped shrub configuration at the territory scale rather than the nest scale, despite strong evidence that Golden-winged Warblers placed nests along edges, suggests that the species may be selecting territories that maximize the number of potential nest sites in anticipation of re-nesting or to reduce predation risk (i.e., potential-prey-site hypothesis). Golden-winged Warbler nest sites had taller (mean height = 4.3 m) and more variable (mean standard deviation of height = 3.1 m) vegetation canopy height than random locations within the same territory. Across a Golden-winged Warbler territory, 40–52% of the tallest vegetation canopy was ≤1 m tall consisting of grasses, forbs, blackberry, and seedlings, 29–33% of the vegetation canopy was >1 to ≤5 m tall consisting of shrubs and saplings, and 15–32% of the vegetation canopy was >5 to ≤20 m tall consisting of trees. I provide one of the first objective evaluations of the spatial configuration of Golden-winged Warbler nesting cover. Part 3 includes chapters 5 – 6 and focuses on Golden-winged Warbler management response. Chapter 5 focused on persistence of breeding Golden-winged Warblers and other disturbance-dependent bird species on pastures with varying amounts of time since abandonment and consequently varying stages of vegetative succession. During 2008–2014, I monitored cattle pastures with varying numbers of years since abandonment representing a 62-year chronosequence. Field Sparrow (Spizella pusilla) density peaked on active pastures, Golden- winged Warbler density peaked 16–20 years after pasture abandonment and reached zero 33 years after abandonment, and shrubland-nesting bird species richness did not vary across the chronosequence. Herbaceous cover peaked on active pastures (0 years since abandonment) at 26% then declined linearly,