Ecological Value and Bird Use of Managed Impoundments and Tidal
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ECOLOGICAL VALUE AND BIRD USE OF MANAGED IMPOUNDMENTS AND TIDAL MARSHES OF COASTAL SOUTH CAROLINA by GRETCHEN E. NAREFF (Under the Direction of Sara H. Schweitzer) ABSTRACT Currently, managed wetlands (impoundments) are manipulated to provide wintering habitat for waterfowl (Anseriformes) and hunting opportunities. Impoundments may be used as supplemental habitat by migrating shorebirds (Charadriiformes) that are facing declines in the quality and quantity of stopover sites. We quantified the species and number of birds present in managed impoundments and tidal marshes during migration and winter seasons with scan sample surveys, documented behavior (e.g., feeding, breeding, roosting) of target bird species with time- activity budgets, and estimated birds’ selection of food items through collection and esophageal dissection. Target bird species were Blue-winged Teal (Anas discors), Green-winged Teal (A. crecca), Greater Yellowlegs (Tringa melanoleuca), and Lesser Yellowlegs (T. flavipes). These data provided information on when and how the birds were using managed impoundments and tidal marshes. Our results suggest that management for multi-species use of impoundments is effective. INDEX WORDS: ACE Basin, Anas crecca, Anas discors, Food items, Impoundment, Managed wetland, Multi-species use, Scan sample, Shorebirds, South Carolina, Teal, Tidal marsh, Time-activity budget, Tringa flavipes, Tringa melanoleuca, Yellowlegs ECOLOGICAL VALUE AND BIRD USE OF MANAGED IMPOUNDMENTS AND TIDAL MARSHES OF COASTAL SOUTH CAROLINA by GRETCHEN E. NAREFF B.S., University of Vermont, 2002 A Thesis Submitted to the Graduate Faculty of The University of Georgia in Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE ATHENS, GEORGIA 2009 © 2009 Gretchen E. Nareff All Rights Reserved ECOLOGICAL VALUE AND BIRD USE OF MANAGED IMPOUNDMENTS AND TIDAL MARSHES OF COASTAL SOUTH CAROLINA by GRETCHEN E. NAREFF Major Professor: Sara H. Schweitzer Committee: Cecil A. Jennings Ernie P. Wiggers Electronic Version Approved: Maureen Grasso Dean of the Graduate School The University of Georgia May 2009 iv DEDICATION This work is dedicated to my parents for their love and support. Also to D.D., E.M., J.M., C.R., A.B., H.M., M.B., T.J., and all of my other friends who spent time with me laughing, complaining, and stressing, but mostly for loving me through it all. I extend a special thank you to B.W., B.S., C.R., and A.H. for showing me how to “walk down another street.” v ACKNOWLEDGEMENTS First, I would like to thank Sara Schweitzer for trusting the folks at the Nemours Wildlife Foundation and taking a chance on someone whom she had never met. This project will no doubt influence the remainder of my career as it sparked in me a love for wetlands and wetland- dependent birds. Your encouragement, guidance, and time will never be forgotten. I must give a special thank you to Ernie Wiggers and Eddie Mills at the Nemours Wildlife Foundation for hiring me as an intern in 2003, fresh out of undergraduate college, with no field experience. Without that opportunity I never would have found my way to the University of Georgia, which has provided me with much more than an education. You both were more than supervisors to me and I will always be grateful for that. Eddie and Juli Mills, you have stuck by me through it all, providing me with love and guidance in life. I am leaving graduate school with a confidence instilled by you both. To Cecil Jennings, Jim Peterson, and Susan Ellis-Felege, I thank you for you assistance with statistical analysis and patience with me through it. My interns and technicians, Ryan, Klimstra, Joseph Hollis, and Daniel Barrineau, my data collection would be incomplete without your work. I thank the Nemours Wildlife Foundation and National Fish and Wildlife Foundation for funding, and Nemours, the USFWS and Hobonny plantation, for field sites, unlimited access, and guidance. Thank you to the Warnell School of Forestry and Natural Resources for this amazing educational and life experience. vi TABLE OF CONTENTS Page ACKNOWLEDGEMENTS.............................................................................................................v LIST OF TABLES......................................................................................................................... ix LIST OF FIGURES ..................................................................................................................... xiii CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW .....................................................1 Impoundment Management.......................................................................................3 Study Overview.........................................................................................................8 Life Histories.............................................................................................................9 Study Area...............................................................................................................14 Literature Cited........................................................................................................15 2 ABUNDANCE OF DABBLING DUCKS AND SHOREBIRDS IN MANAGED IMPOUNDMENTS AND TIDAL MARSHES OF COASTAL SOUTH CAROLINA ............................................................................................................25 Abstract ...................................................................................................................26 Introduction .............................................................................................................27 Study Area...............................................................................................................29 Methods...................................................................................................................31 Results .....................................................................................................................34 Discussion ...............................................................................................................35 vii Acknowledgements .................................................................................................41 Literature Cited........................................................................................................41 3 TIME-ACTIVITY BUDGETS OF TEAL AND YELLOWLEGS IN MANAGED IMPOUNDMENTS AND ADJACENT TIDAL MARSHES.................................57 Abstract ...................................................................................................................58 Introduction .............................................................................................................59 Study Area...............................................................................................................61 Methods...................................................................................................................62 Results .....................................................................................................................64 Discussion ...............................................................................................................66 Acknowledgements .................................................................................................70 Literature Cited........................................................................................................71 4 FOOD HABITS OF TEAL AND YELLOWLEGS IN MANAGED IMPOUNDMENTS OF THE SOUTH ATLANTIC...............................................84 Abstract ...................................................................................................................85 Introduction .............................................................................................................86 Study Area...............................................................................................................90 Methods...................................................................................................................90 Results .....................................................................................................................93 Discussion ...............................................................................................................94 Acknowledgements .................................................................................................98 Literature Cited........................................................................................................98 5 CONCLUSIONS........................................................................................................109 viii Future Research.....................................................................................................110 Management Recommendations ...........................................................................112 Literature Cited......................................................................................................114 APPENDICES .............................................................................................................................117 A List of all avian species detected in 2007 and 2008 on experimental units at the Ernest F. Hollings Ashepoo-Combahee-Edisto Basin National Wildlife Refuge and Nemours Wildlife Foundation, Beaufort County, SC ...........................................118 B Permits required for collection of teal and yellowlegs for