Date of Graduation
Davis College of Agriculture, Natural Resources and Design
Wildlife and Fisheries Resources
Christopher M. Lituma
Petra B. Wood
Kyle R. Aldinger
The USDA - Natural Resources Conservation Service (NRCS) supports private lands conservation across the United States to benefit imperiled focal wildlife species using conservation practices to restore habitat. Through the Cerulean Warbler (Setophaga cerulea) Forestland Enhancement Project (CWAFEP) and the Working Lands for Wildlife (WLFW) Golden-winged Warbler (Vermivora chrysoptera) initiative, the NRCS provides technical and financial assistance to private landowners to implement conservation practices that follow science-based habitat management guidelines. Few research studies have evaluated focal species-specific occupancy on CWAFEP and/or WLFW sites, and research is required to inform each conservation project’s effectiveness in an adaptive management framework. This thesis includes 4 chapters which focus on avian occupancy and species richness on CWAFEP and WLFW sites in West Virginia.
In chapter 1, I provide a brief introduction and justification for my research. This chapter summarizes each project’s background and the importance of evaluation efforts. Also included in chapter 1 is an overview of Blue-winged Warbler (Vermivora cyanoptera) ecology and their relevance to the following thesis chapters.
In chapter 2, I evaluate Cerulean Warbler and forest focal species occupancy and avian guild species richness on CWAFEP sites treated using to conservation practices. During May – July 2019 – 2020, I conducted point count surveys at 194 locations on 21 CWAFEP sites in West Virginia. There were no differences in Cerulean Warbler occupancy estimates at untreated and treated locations. Cerulean Warbler occupancy decreased by 91% as elevation increased from 200 to 800 m and increased by 397% as sapling cover increased from 0 to 100%. Occupancy for three forest focal species and species richness in four avian guilds also were not different at untreated and treated locations. My study indicates that Cerulean Warbler and the avian community were not positively correlated with recent conservation practice implementation (1 – 4 years post-treatment) and that CWAFEP must adhere more strictly to the recommended guidelines if it is going to be effective for Cerulean Warbler conservation. I suspect that the lack of differences in occupancy and species richness estimates was due to private lands variability, site selection, small treatment areas, and challenges associated with private lands conservation resulting in insufficient basal area removal. Basal area was above the recommended range of 9.2 – 20.7 m 2/ha (40 – 90 ft 2/ac) at 40% of post treatment sampling locations. I recommend all CWAFEP sites achieve the recommended basal area range of 9.2 – 20.7 m 2/ha (40 – 90 ft 2/ac) during contract implementation and refinement of the CWAFEP focal area in West Virginia to improve the project’s effectiveness.
In chapter 3, I evaluate Vermivora and shrubland focal species occupancy and species richness of avian guilds on WLFW sites treated using conservation practices. During May – July 2019 – 2020, I conducted point count surveys at 147 locations on 22 private properties enrolled in WLFW in West Virginia. There were no differences in Vermivora occupancy estimates at untreated and treated locations. Vermivora occupancy increased by 967% as 100-m shrubland increased from 0 to 100% cover and decreased by 87% as 100-m basal area increased from 0 to 30 m2/ha. Occupancy for 1 of the 3 shrubland focal species and species richness in all avian guilds also were not different at untreated and treated locations, suggesting that conservation practices did not meaningfully influence associated shrubland bird occurrence or avian diversity. My study indicates that Vermivora and the avian community were not positively correlated with recent conservation practice implementation in the short-term (1 – 8 years post-treatment) and that WLFW must adhere more strictly to the recommended guidelines if it is going to be effective for Golden-winged Warbler conservation. I recommend additional basal area removal to within the recommended range of 1.9 – 3.7 m 2/ha (8.3 – 16.1 ft 2/ac) during contract implementation and restriction of the WLFW focal area to higher elevations (>600 m) to improve the project’s effectiveness.
Finally, chapter 4 focused on identifying key habitat characteristics associated with Blue-winged Warbler occupancy on sites enrolled in CWAFEP and WLFW. Included in analysis were all 341-point count locations from 19 CWAFEP sites, 20 WLFW sties, and 2 sites enrolled in both projects. Treated points had lower occupancy than untreated points by 34 – 44% depending on ecoregion. Occupancy was greatest in the Central Appalachian ecoregion, but I detected Blue-winged Warblers across the range of elevations surveyed (244 – 917 m), suggesting that their breeding distribution is continuing to expand into higher elevations in the Appalachians. Occupancy increased by 772% as 100-m shrubland increased from 0 to 100% cover and increased by 790% as 100-m young forest/shrubland increased from 0 to 100% cover. Occupancy decreased by 91% as 100-m basal area increased from 0 to 30 m2/ha. NRCS conservation projects for Cerulean Warbler and Golden-winged Warbler generally did not produce conditions to increase occupancy of Blue-winged Warblers. I recommend 50 – 100% shrubland cover at the 100-m radius scale and residual basal area of 0.0 – 4.6 m2/ha (0 – 20 ft2/ac) when managing habitat for Blue-winged Warblers in the Appalachians.
Overall, my findings help to justify, inform, and adapt NRCS conservation efforts for Cerulean and Golden-winged Warblers. The information I have provided in this thesis fills scientific knowledge gaps for Cerulean, Golden-winged, and Blue-winged Warblers and provides useful feedback to NRCS following an adaptive management framework.
Oliver, Lincoln R., "Evaluating Avian Occupancy On Sites Treated With NRCS Conservation Practices Implemented To Benefit Cerulean (Setophaga Cerulea) and Golden-Winged Warblers (Vermivora Chrysoptera) in West Virginia" (2021). Graduate Theses, Dissertations, and Problem Reports. 8001.