Monitoring and Evaluating Golden-Winged Warbler Use of Breeding Habitat Created by the Natural Resources Conservation Service Practices
Total Page:16
File Type:pdf, Size:1020Kb
Monitoring and Evaluating Golden-winged Warbler Use of Breeding Habitat Created by the Natural Resources Conservation Service Practices A Conservation Effects Assessment Project (CEAP) Cooperative agreement # 68-7482-12-502 Phase I: 2012-14 Final Report Prepared by: Kyle Aldinger, West Virginia Cooperative Fish and Wildlife Research Unit, West Virginia University; Marja Bakermans, Department of Biology and Biotechnology, Worcester Polytechnic Institute; Jeffery Larkin, Department of Biology, Indiana University of Pennsylvania and American Bird Conservancy; Justin Lehman, Department of Forestry, Wildlife and Fisheries, University of Tennessee; D.J. McNeil, Jr., Department of Biology, Indiana University of Pennsylvania; Anna Tisdale, Biology Department, Appalachian State University Corresponding Author: Dr. Jeffery Larkin, [email protected] or 724-357-7808 Partners: David Buehler, Department of Forestry, Wildlife, and Fisheries, University of Tennessee, Knoxville, TN 37996 Petra Wood, US Geological Survey West Virginia Cooperative Fish and Wildlife Research Unit, West Virginia University, Morgantown, WV 26506 Curtis Smalling, Director of Land Bird Conservation, Audubon North Carolina, Boone, NC 28607 Lynn Siefferman, Department of Biology, Appalachian State University, 572 Rivers Street, Boone, NC 28608-3027 Todd Fearer, Appalachian Mountain Joint Venture/American Bird Conservancy, Conservation Management Institute (CMI), Blacksburg, VA 24061 Graduate students: Kyle Aldinger, Division of Forestry and Natural Resources, West Virginia University; Justin Lehman, Department of Forestry, Wildlife and Fisheries, University of Tennessee; D.J. McNeil, Jr., Department of Biology, Indiana University of Pennsylvania; Anna Tisdale, Biology Department, Appalachian State University 1 Contents STUDY OVERVIEW ................................................................................................................................... 3 Report Layout ................................................................................................................... 3 Project Summary .............................................................................................................. 3 Introduction ...................................................................................................................... 4 Project Goals .................................................................................................................... 6 STUDY SITE AND MANAGEMENT SYSTEMS ..................................................................................... 7 Study Sites ........................................................................................................................ 7 Management Systems ....................................................................................................... 9 STUDY COMPONENTS ........................................................................................................................... 12 Study Component I: Comparison of study site size and vegetation across management systems ..................................................................................................................... 12 Study Component II: Annual adult male survival and body condition index among management systems ............................................................................................... 16 Study Component III: Estimating avian density using point count surveys .................. 20 Study Component IV: Characterizing breeding bird communities across management systems ..................................................................................................................... 31 Study Component V: Estimating territory size and density across management systems using territory mapping ............................................................................................ 34 Study Component VI: Evaluation of nest-site selection and nest survival and productivity among management systems ............................................................... 42 Component VII: Post-fledging survival, movements, and habitat use of juvenile Golden-winged Warblers ......................................................................................... 56 Study Component VIII: Investigating space-use of adult male Golden-winged Warblers using radio-telemetry……………………………………………………………...68 Study Component IX: Relationships between male plumage ornamentation, region, and management systems ............................................................................................... 78 DISCUSSION ............................................................................................................................................. 88 Acknowledgments .......................................................................................................... 94 Literature Cited .............................................................................................................. 95 Appendices ................................................................................................................... 100 2 STUDY OVERVIEW Report Layout This report describes each aspect of the Conservation Effects Assessment Project (CEAP) research conducted by Golden-winged Warbler Working Group partners in the Appalachian Mountains over the past three years (i.e., 2012 - 2014). The report begins with a background discussion, brief overview of the CEAP project, and an explicit summary of the objectives of this study. These introductory sections not only inform the reader about this project as a whole, but outline the importance of this work and conservation efforts for the Golden-winged Warbler, in general. The sections that follow are the finer components of this CEAP study that are each laid out in detail. Each aspect of study is subdivided into independent sections, each complete with a short summary presenting background and rationale, methods describing how the work was conducted, and results which describes the important findings of each component of study. Within each component of this study (n = 9 components), all figures and tables are shown (referenced within the text). Finally, an overall discussion of this study is presented in the “Project Discussion” section at the conclusion of this document. All citations for literature referenced within this document are listed at the end of this report. For more details regarding navigation of this document, see the Table of Contents (page 2). Project Summary The Golden-winged Warbler (Vermivora chrysoptera) is a Neotropical migrant bird that breeds in young forest habitats and is experiencing steep population declines throughout the Appalachian Mountains breeding range (8.5% year-1 [95% CI 7.1 – 9.8], Sauer et al. 2014). One cause of population decline is loss of breeding habitat, and conservation of this species requires active habitat management. In this study, we monitored and evaluated Golden-winged Warbler response to habitat management using conservation practices suggested by the Natural Resource Conservation Service’s (NRCS) Working lands For Wildlife (WLFW): Golden-winged Warbler Habitat Initiative in the southern and central Appalachian states. We examined density, nest success, juvenile survival and movements, adult condition and survival, and habitat selected by Golden-winged Warblers at study sites placed into five NRCS management systems groupings: timber harvest, prescribed fire- young forest, prescribed fire- old field, grazing management, and old field management. In 2012-2014, we conducted 864 point count surveys, banded 800 birds, mapped 739 territories, and monitored nesting success of 337 Golden-winged, Blue-winged (Vermivora cyanoptera), and hybrid Warbler nests across 95 sites in North Carolina, Pennsylvania, Tennessee, and West Virginia. Further, we analyzed the plumage of 135 individual males, radio-tracked 7 adult males on territory, and radio-tracked 89 fledglings. We also collected vegetation data to characterize each site (n = 2,347 vegetation plots), Golden- winged Warbler nest plot (n = 317), and associated random plot (n = 317). Analyses from 2012-2014 indicated that many of the measured metrics (e.g., density and nesting survival) did not differ among the 5 management systems, thus indicating similar 3 capabilities to support breeding Golden-winged Warblers. At the same time, this report identifies vegetation characteristics that can be manipulated to improve habitat within management systems. For example, across management systems, increased attention to attaining preferred levels of grass cover (5-25%/1-m radius) from the Golden-winged Warbler Breeding Season Conservation Plan (Roth et al 2012) may result in increased availability of nest sites. Furthermore across management systems, increased attention to attaining levels of Rubus spp. cover (13-48%/1-m radius) consistent with high-quality nest sites may result in increased nest survival. On average, managed sites supported 1.51 males/10 ha, where males had a 0.58 (± 0.04) minimum annual survival rate and produced 0.51 (± 0.05) fledglings/ha. Predicted Golden- winged Warbler density from point counts increased with elevation at southern sites but decreased with elevation at northern sites. Telemetry data on juvenile and adult Golden-winged Warbler movements and habitat use demonstrated that birds use multiple stages of succession (i.e., early, mid, and late successional forest) during the breeding and post-breeding periods. Additionally,