Breeding Bird and Vegetation Communities of Reelfoot Lake
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University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Masters Theses Graduate School 5-2004 Breeding Bird and Vegetation Communities of Reelfoot Lake Nicholas Alan Winstead University of Tennessee, Knoxville Follow this and additional works at: https://trace.tennessee.edu/utk_gradthes Recommended Citation Winstead, Nicholas Alan, "Breeding Bird and Vegetation Communities of Reelfoot Lake. " Master's Thesis, University of Tennessee, 2004. https://trace.tennessee.edu/utk_gradthes/5325 This Thesis is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Masters Theses by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a thesis written by Nicholas Alan Winstead entitled "Breeding Bird and Vegetation Communities of Reelfoot Lake." I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Master of Science, with a major in Wildlife and Fisheries Science. David A. Buehler, Major Professor We have read this thesis and recommend its acceptance: Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) To the Graduate Council: I am submitting herewith a thesis written by Nicholas Alan Winstead entitled "Breeding Bird and Vegetation Communities of Reelfoot Lake." I have examined the final paper copy of this thesis for form and content and recommend that it be accepted in partialfulfillment of the requirements for the degree of Master of Science, with a major in Wildlife and Fisheries Science. David A. Buehler, Major Professor We have read this thesis and recommend its acceptance: William G. Minser Acceptance for the Council: Vice Chancellor and Dean of Graduate Studies BREEDING BIRD AND VEGETATION COMMUNITIES OF REELFOOT LAKE A Thesis Presented for the Master of Science Degree The University of Tennessee, Knoxville Nicholas Alan Winstead May 2004 DEDICATION This thesis is dedicated to my parents, Jan and Kendell Winstead. Without their love, encouragement, guidance, and support through a lot of long years I would not be where I am now. ii ACKNOWLEDGEMENTS I want to thank everyone that helped me during the past few years. would like to thank my major advisor, Dr. Sammy King, for all of his guidance. would also like to thank my committee members, Dr. David Buehler and Mr. Billy Minser, for their help and interest in my project. I would not have been able to do any of this without funding from the Departmentof Forestry, Wildlife, and Fisheries at The University of Tennessee, Knoxville. I thank Dr. M. Gore Ervin, editor of the Journal of the Tennessee Academy of Science, for granting permission to use a figure from the Journal (Figure 2 in this thesis). I want to give special thanks to Paul Brown and David Sams with the Tennessee Wildlife Resources Agency forproviding lodging, boats, and putting up with all kinds of inconveniences during two field seasons. Finally, I want to thank my friends and family for helping me through the frustrating times - especially my fellow graduate students in Sammy's lab and the bird lab. iii ABSTRACT Emergent plant communities at Reelfoot Lake were once dominated by giant cutgrass (Zizaniopsis miliacea). Cutgrass was used by relatively large numbers of secretive marsh birds, such as least bitterns (/xobrychusexilis). Water levels were stabilized in the early 1940s, which allowed cutgrass marshes to succeed to water willow (Decodon verticillatus) marshes. There is no information on the extent of water willow or its value to breeding birds on Reelfoot Lake. The objectives of this study were to 1) determine the extent and type of emergent plant communities on Reelfoot, 2) describe the breeding avian communities using these emergent plant communities, and 3) evaluate an interim nationwide secretive marsh bird monitoring protocol. During 2003, I used printed DOQQs to ground-truth emergent plant communities on Reelfoot. I determined that 93% of the emergent marsh was dominated by water willow. Cutgrass- and cattail-dominated marshes made up the remainder. Most marshes had a substantial amount of woody growth. Secretive marsh bird surveys and habitat data collection were conducted on Reelfoot and nearby Black Bayou during the 2003 breeding season. A total of 66 observations were made of 4 species during surveys, including least bitterns, pied-billed grebes (Podilymbus podiceps), common moorhens ( Gallinula chloropus), and king rails (Rallus elegans). American coots (Fulica americana) were also observed, but not during surveys. Logistic regression with stepwise selection found least bitterns were positively related to the percent cover of iv cutgrass (parameter estimate = 7.76, Wald chi-square = 4.70, P< 0.04). Over 90% of plots with� 20% cutgrass had at least 1 least bittern. In contrast, only 50% of plots with< 20% cutgrass had at least 1 least bittern. A 20-ha cutgrass dominated unit on Black Bayou had greater species richness than surveyed areas on Reelfoot Lake. Apparent declines of secretive marsh birds on Reelfoot have coincided with the replacement of cutgrass by water willow. Songbird surveys and habitat data collection were conducted during the 2002 and 2003 breeding seasons. Several species of songbirds associated with closed-canopy forests were found in the marshes on Reelfoot. These birds were negatively associated with cutgrass (parameter estimate = -0.258, Wald chi square = 5.19, P< 0.03) but positively related to percent cover of woody species (parameter estimate = 0.06, Wald chi-square = 2.85, P< 0.10). This indicates that as woody species increase at the expense of marsh vegetation, Reelfoot bird communities may shift from marsh-dependent species to those associated with closed-canopy fofests. If management for secretive marsh birds and marsh songbirds becomes a goal on Reelfoot Lake, vegetation manipulation may be necessary. A drawdown and possibly other management tools with the goals of replacing water willow with sparse stands of cutgrass and reducing woody vegetation may improve breeding habitat for many species of marsh-dependent birds on Reelfoot Lake. V TABLE OF CONTENTS 1.INTRODUCTION ............................................................................................... 1 GENERAL LAKE AND WATERSHED DESCRIPTION ..................................... 1 CREATION OF REELFOOT LAKE ................................................................... 2 ORIGINAL VEGETATION ................................................................................. 2 EARLY SETTLEMENT AND OWNERSHIP ...................................................... 3 WATER-LEVEL MANIPULATIONS .................................................................. 4 PROBLEMS AND PROPOSED SOLUTIONS ................................................... 7 RESEARCH NEEDS ....................................................................................... 13 OBJECTIVES .................................................................................................. 14 2. PLANT COMMUNITIES .................................................................................. 15 INTRODUCTION ............................................................................................ 15 EARLY HYDROLOGICAL MANIPULATIONS ................................................. 15 BEGINNINGS OF WIDESPREAD VEGETATION GROWTH ......................... 17 BEGINNINGS OF VEGETATION CHANGES ................................................. 20 RECENT PLANT COMMUNITY STUDIES ..................................................... 21 OBJECTIVES .................................................................................................. 24 METHODS ...................................................................................................... 24 RESULTS AND DISCUSSION ........................................................................ 25 3. SECRETIVE MARSH BIRDS ......................................................................... 29 INTRODUCTION ............................................................................................ 29 OBJECTIVES .................................................................................................. 35 METHODS ...................................................................................................... 35 RESULTS ....................................................................................................... 40 DISCUSSION.................................................................................................. 45 4. MARSH SONGBIRDS .................................................................................... 57 INTRODUCTION ............................................................................................ 57 OBJECTIVES .................................................................................................. 58 METHODS ...................................................................................................... 58 RESULTS ....................................................................................................... 59 DISCUSSION .................................................................................................. 60 5. MANAGEMENT IMPLICATIONS