Golden-winged Warbler Working Group (D.A. Buehler, chair). 2019. Golden-winged Warbler full life cycle conservation strategy. In Roth, A.M., R.W. Rohrbaugh, T. Will, S. Barker Swarthout, and D.A. Buehler, editors. 2019. Golden-winged War-bler Status Review and Conservation Plan. 2nd Edition. www.gwwa.org/committees.html
Illustration by Bartels Science Illustrator Evaristo Hernandez Fernandez
Author:
Golden-winged Warbler Working Group, www.gwwa.org/committees
ACKNOWLEDGMENTS
The Golden-winged Warbler Conservation Plan was developed and reviewed under the guidance of the Golden-winged Warbler Working Group, a consortium of more than 140 biologists and managers engaged in research and conservation of this species, www.gwwa.org/. Funding for the initiative was provided by the National Fish and Wildlife Foundation and U.
S. Fish & Wildlife Service, with more than $1 million in matching contributions provided by numerous partner organizations including American Bird Conservancy, Appalachian Mountains Joint Venture, Audubon North Carolina, Cornell Lab of Or-nithology, Fundacion Proaves-Colombia, Indiana University of Pennsylvania, Ithaca College, Michigan Technological Uni-versity, University of Minnesota, University of Tennessee, Wisconsin Department of Natural Resources, Tennessee Wildlife Resources Agency, and The Ruffed Grouse Society. We are grateful to the many individuals who contributed significant effort to specific portions of this document, as follows:
Breeding Season Research Team
Kyle Aldinger, Sara Barker Swarthout, David Buehler, Lesley Bulluck, John Confer, David Flashpohler, Monica Fowlds, Jeff Larkin, John Loegering, Irby Lovette, Karl Martin, Ron Rohrbaugh, Ken Rosenberg, Amber Roth, Curtis Smalling, Laura Stenzler, Rachel Vallender, and Petra Wood
Conservation Plan Analytical Team
Primary analysis for Conservation Plan: Dolly Crawford and Theron Terhune
Additional members of analytical team: Sara Barker Swarthout, David Buehler, Jim Lowe, Martin Piorkowski, Ron Rohr-baugh, Ken Rosenberg, and Amber Roth
Design Team
Primary design for Conservation Plan: Sara Barker Swarthout
Additional members of design team: Joanne Avila, Jim Lowe, Reyn Ojiri, Diane Tessaglia-Hymes, Ann-Kathrin Wirth, and Janet Menninger
Conservation Plan Contributors
Jeff Bolsinger, Gwen Brewer, Ron Canterbury, Kelly Caruso, Lauren Chaby, Joe Chernek, Caitlin Emro, Carol Hardy Croy, Randy Dettmers, Paul Elsen, Marisol Escaño, Marilyn Gonzalez, Doug Gross, Sergio Harding, Austin Hicks, Eduardo Ini-go-Elias, Chris Kelly, Tom Langen, R. Scott Lutz, Eric Miller, Dennis Miranda, Maria Isabel Moreno, Katie Percy, Sharon Petzinger, Brian Roden, Tom Rogers, Aaron Swartwood, Rob Tallman, Jason Tesauro, William Tolin, Shawchyi Vorisek, Christopher Webster, Melinda Welton, David Wiedenfeld, and John Wojcikiewicz
External Reviewers
Jeff Bolsinger, Dan Eklund, Todd Fearer, Sergio Harding, Carol Hardy Croy, Andy Hinickle, Ben Jones, Michelle McDowell, Kathy St. Laurent, and Gary Zimmer
CHAPTER 2. TABLE OF CONTENTS
AUTHORS: . . . .2–1 RECOMMENDED CITATION . . . .2–1 ACKNOWLEDGMENTS . . . 2–2 CHAPTER 2 SUMMARY . . . 2–4 CONSERVATION STRATEGY . . . 2–5 Canadian Recovery Strategy . . . 2–8 Associated Species and Plans . . . 2–9 CONSERVATION ACTIONS . . . .2–12
Goal 1: Understand the full lifecycle of the Golden-winged Warbler to identify factors
most likely limiting regional and global populations. . . . .2–12 Goal 2: Reduce threats to Golden-winged Warbler populations during the breeding stationary period. . . .2–13 MANAGEMENT AND CONSERVATION STRATEGIES . . . .2–13 INFORMATION NEEDS . . . .2–14 COMMUNICATIONS AND CAPACITY BUILDING . . . .2–15
Goal 3: Reduce threats to Golden-winged Warbler populations during the migratory
and non-breeding stationary periods. . . . .2–16 MANAGEMENT AND CONSERVATION STRATEGIES . . . .2–16 INFORMATION NEEDS . . . .2–16 COMMUNICATIONS AND CAPACITY BUILDING . . . .2–17
CHAPTER 2 SUMMARY
G
olden-winged Warbler (Vermivora chrysoptera) populations have declined significantly across their breeding range for the past 45 years, based on analysis of North American Breeding Bird Survey (BBS) data. The eastern portion of the breeding population, primarily in the Appalachian Mountains Bird Conservation Region, has declined precipitously and is now largely disjunct from the Midwestern (Great Lakes) populations. Midwestern populations, which now comprise the vast majority of breeding pairs, are now starting to decline as well. Much of the decline of this species can be explained by habitat loss, while hybridization with Blue-winged Warbler (Vermivora cyanoptera) has exacerbated the declines and added complexity to the development of effective conservation strategies. These themes related to Golden-winged Warbler biology, ecology, and population status are further explored in Chapter 1 of this Status Review and Conservation Plan.The Golden-winged Warbler Working Group was established in 2003 to provide a coordinated response to the declining Golden-winged Warbler populations. The Working Group has developed this full life cycle conservation strategy for this species based on contemporary knowledge about its breeding, migration, and wintering ecology. The strategy is based on the presumption that limiting factors on the breeding grounds, during migration, and on the wintering grounds need to be addressed to effectively counteract the factors currently responsible for population declines. On the breeding grounds, this strategy is based on delineation of focal conservation areas where maintenance of breeding populations is being promoted through implementation of habitat management guidelines. These guidelines (Chapter 3) have been developed based on a cooperative research project documenting habitat characteristics and relationships with successful nesting (see sidebar, page 2–9). The Working Group will conduct training workshops for public and private land managers to get knowledge about Golden-winged Warbler habitat prescriptions into the hands of people that can affect habitat management. Additional work is needed to delineate the migration pathways for Golden-winged Warbler to allow for the development of specific conservation strategies to protect migration stopover areas. The Working Group is also working on the wintering grounds to document distribution and habitat associations, and develop proactive conservation strategies to protect and restore quality wintering habitat that will ensure successful over-winter survival (Chapter 4). Success of the conservation strategy will be assessed through a coordinated monitoring program. This monitoring program will track the key components of the con-servation strategy, including acres managed for Golden-winged Warbler, population response at multiple spatial scales, and changes in levels of genetic introgression within populations.
This conservation strategy has been developed with the needs of other priority species in mind. The species associated with Golden-winged Warbler have been identified in this document. We have also forged a working relationship with the regional Young Forest Initiatives (www.youngforest.org) coordinated by the Wildlife Management Institute, among others, to avoid duplication of effort and benefit from synergistic activities.
For your reference, a glossary of commonly used terms is provided in Appendix A. Other useful sources of information about Golden-winged Warbler are listed in Appendix B.
Understanding a species’ ecology and demography through-out its life cycle is the key to identifying the factors leading to population decline or limiting population growth (see sidebar). Until we have definitive evidence identifying spe-cific limiting factor(s); however, we advocate a full life cycle strategy to conservation that includes addressing several identified threats:
1. Increasing quality and quantity of breeding, stop-over, and wintering habitats.
2. Minimizing hybridization with the closely related Blue-winged Warbler.
3. Promoting research into refining our understanding of the factor(s) leading to population decline and recovery.
The primary premise behind this conservation strategy is that reproductive output may be increased by increasing the amount of habitat and by improving the quality of exist-ing habitat. This straightforward notion; however, is com-plicated by the Golden-winged Warbler’s interactions with the closely related Blue-winged Warbler. In some areas, therefore, suitable habitat might not be occupied by Gold-en-winged Warblers if Blue-winged Warblers are present.
For this reason, land managers should seek to create habitat in locations and configurations that promote persistence of Golden-winged Warbler populations and minimizes inter-actions with Blue-winged Warblers.
The conceptual model in Figure 2–1A describes the strategic plan for Golden-winged Warbler conservation. This logic framework was originally developed as part of the National Fish and Wildlife Foundation’s Early Successional Habitat (ESH) Initiative business plan. Included are the key com-ponents needed for successful implementation to meet the stated population goals with an emphasis on a full life cy-cle conservation approach. Figure 2–1B and C details the process being implemented by the Golden-winged Warbler Working Group to address conservation during the breeding and nonbreeding seasons. Though this document addresses rangewide and regional planning needs, additional meet-ings and planning may be needed at the state and local level to assist agencies with implementation. The next phase of implementation will require collaboration between a broad range of partners to protect and manage breeding habi-tat. The Golden-winged Warbler Working Group will play a fundamental role in providing technical assistance and outreach tools to assist partners in this next phase. Though baseline information on breeding habitat management has been collected, ongoing evaluation of management tools and guidelines will be necessary to improve our effect on populations.
The primary strategy for increasing Golden-winged War-bler populations on the breeding range is through creation, restoration, and maintenance of high quality habitat on a landscape scale. The progression of management phases
toward population recovery will follow a conceptual mod-el similar to that devmod-eloped by the Royal Society for the Protection of Birds (Figure 2–2). The current focus for the Golden-winged Warbler Working Group and partners is to implement large-scale, adaptive management aimed at pop-ulation recovery in places where further experimentation is either unnecessary or where there are locations and habi-tat types that have received little previous research. It will be important to evaluate population response at all phases of management to track progress toward population goals.
Continued research will be needed to fill gaps in our knowl-edge about habitat suitability and to evaluate new manage-ment techniques and strategies. Given that ESHs can quick-ly succeed out of suitability for Golden-winged Warbler, all strategies will need to consider that the amount of available habitat may change over time. The rate of habitat turnover will vary depending on habitat type. For example, given poor site conditions and slow succession, reclaimed surface mines might remain suitable for decades, while an aspen clearcut might become unsuitable in as few as ten years.
Long-term conservation plans should include provisions for habitat creation (e.g., timber harvesting), restoration (e.g., removing some trees and shrubs in old fields), and mainte-nance (e.g., periodic use of fire, brush-hogging, or grazing to slow succession). New research following survival of Gold-en-winged Warbler through fledging (Streby and Andersen, pers. comm.) suggests that the Golden-winged Warbler is a bird of forested landscapes that depends on multiple seral
Example of Factors Limiting Population Growth Imagine that a population is like water in a leaky buck-et. Because there are holes in the bucket, the water is continually draining out; this represents mortality in a population. To maintain the water level in the bucket, more water must be added periodically; this represents reproduction and recruitment into a population. If the rate of the water leaking from the bucket is equal to the water entering the bucket, then a population is stable. If the rate of the water leaking from the buck-et exceeds the rate of the water entering the buckbuck-et, then a population is declining, as is the case for the Golden-winged Warbler. To increase population size, there are two options: 1) increase reproductive output (i.e. increase the rate of adding water to the bucket), and/or 2) increase annual survival and recruitment to the population. By increasing reproductive output, we can potentially increase a population, but this will be limited by the breeding ecology of the species. Gold-en-winged Warblers are single-brooded and produce at most 5–6 young per brood. If the rate of mortality exceeds the maximum reproductive potential of the species, then other conservation actions will be neces-sary for population recovery.