Microhabitat associations of wintering birds in a Southeastern bottomland forest within the Eastern Gulf Coastal Plain of Florida

MICROHABITAT ASSOCIATIONS OF WINTERING BIRDS IN A

SOUTHEASTERN BOTTOMLAND FOREST WITHIN THE

EASTERN GULF COASTAL PLAIN OF FLORIDA

Except where reference is made to the work of others, the work described in this thesis is
my own or was done in collaboration with my advisory committee. This thesis does not
include proprietary or classified information.

________________________________
Brian William Rolek

Certificate of approval:

________________________________
Barry J. Grand
Associate Professor
Forestry and Wildlife Sciences

________________________________
Geoffrey E. Hill, Chair
Professor
Biological Sciences

________________________________
Troy L. Best
Alumni Professor
Biological Sciences

________________________________
George T. Flowers
Dean
Graduate School

MICROHABITAT ASSOCIATIONS OF WINTERING BIRDS IN A

SOUTHEASTERN BOTTOMLAND FOREST WITHIN THE

EASTERN GULF COASTAL PLAIN OF FLORIDA

Brian William Rolek

A Thesis

Submitted to
the Graduate Faculty of

Auburn University

in Partial Fulfillment of the
Requirements for the Degree of
Master of Science

Auburn, AL
August 10, 2009

MICROHABITAT ASSOCIATIONS OF WINTERING BIRDS IN A

SOUTHEASTERN BOTTOMLAND FOREST WITHIN THE

EASTERN GULF COASTAL PLAIN OF FLORIDA

Brian William Rolek
Permission is granted to Auburn University to make copies of this thesis at its discretion,
upon request of individuals or institutions and at their expense. The author reserves all
publication rights.

________________________________
Signature of Author

________________________________
Date of Graduation

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VITA
Brian William Rolek, son of William Rolek and Donna Wroblewski, was born 5
November 1980 in Media, Pennsylvania. He graduated from Malvern Preparatory
School in 1998 where he played ice hockey. He attended the University of
Massachusetts in Amherst, Massachusetts, where he volunteered for research on
Chestnut-sided Warblers which sparked his interest in conservation and birds. He
graduated with a Bachelor of Science degree in biology in May, 2003. After working as
a technician researching Eastern Bluebirds for Auburn University Biological Sciences
Department, he entered Graduate School, Auburn University, in August, 2006.

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THESIS ABSTRACT
MICROHABITAT ASSOCIATIONS OF WINTERING BIRDS IN A

SOUTHEASTERN BOTTOMLAND FOREST WITHIN THE
EASTERN GULF COASTAL PLAIN OF FLORIDA

Brian William Rolek

Master of Science, August 10, 2009
(B.S. University of Massachusetts, 2003)

55 Typed Pages

Directed by Geoffrey E. Hill

I examined microhabitat characteristics affecting the occupancy of wintering birds
in a southeastern bottomland forest with repeated point counts at 186 sites. Models were
derived a priori based on published literature and personal observations. I assessed 34
species and their microhabitat preferences within the Choctawhatchee River Basin. I
then created microhabitat groups based on all habitat associations that allowed for a
simplified interpretation of results. Microhabitat characteristics were important for 25 of
34 species of birds and were important predictors their occupancies 34 times. The

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occupancy of species was influenced similarly by physiognomic and floristic
characteristics; the former influenced occupancy of 12 species and the latter occupancy of
19 species. The basal area of Tupelo (Nyssa) was the most important floristic predictor,
and for five of six species it negatively affected the presence of birds. Number of woody
stems (< 10 cm dbh) was the most important physiognomic predictor of species
occupancy. Woody stems affected occupancies of four species. Presence of standing
water and oak-hickory (Quercus + Carya aquatica) community affected occupancies of
three species. Oak-gum-cypress (Quercus + Nyssa + Taxodium distichum) community
affected occupancies of two species. The probability of detecting birds was most
frequently affected by date and observer differences. Also affecting the probability of
detection were wind, temperature, and time after sunrise. Microhabitat is an important
component of habitat selection by birds and should be incorporated into models of
occupancy that are used for conservation purposes. My study provides empirically tested
associations between occupancy and microhabitat characteristics, and can provide a
starting point for future habitat modeling efforts.

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ACKNOWLEDGEMENTS
The author would like to thank first and foremost my family: Bill, Donna, Chris,
and Jackie Rolek, for their constant support and encouragement. Thanks are also due to
the many friends that made my time at Auburn University a unique, educational, and
entertaining experience. Unfortunately, there are too many to properly acknowledge
here. Your company and much needed distractions made time spent in Auburn
memorable and authentic. I especially appreciate Austin Mercadante and Chris McClure
for their friendship, encouragement, and constructive critiquing. Geoffrey Hill and Barry
Grand deserve infinite thanks for their constant encouragement and thoughtful advice.
Troy Best’s support in a pinch was invaluable.

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Journal style: The Auk published by the American Ornithologists Union
Computer software: Microsoft Word 2003, Microsoft Excel 2003, Presence 2.2, SPSS,
Open Office Calc 3.0

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TABLE OF CONTENTS
LIST OF TABLES ............................................................................................................. xi
LIST OF FIGURES .......................................................................................................... xii

INTRODUCTION 1.1 .................................................................................................... 1
METHODS 1.2 ............................................................................................................... 6

Study Site .................................................................................................................... 6
Sampling Design and Surveys .................................................................................... 7
Statistical Analysis...................................................................................................... 9

Hypotheses Construction ........................................................................................ 9
Occupancy Analyses ............................................................................................. 10
Microhabitat Grouping.......................................................................................... 10

RESULTS 1.3 ............................................................................................................... 11
Variables Affecting Detectability ............................................................................. 11
Occupancy Overview ................................................................................................ 12
Physiognomic Effects on Occupancy ....................................................................... 12
Floristic Effects on Occupancy ................................................................................. 13

DISCUSSION 1.4 ......................................................................................................... 14
LITERATURE CITED 1.5 ........................................................................................... 23
APPENDIX I. ................................................................................................................... 38

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APPENDIX II. .................................................................................................................. 40

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