Foraging ecology and habitat use of wading birds and shorebirds in the mangrove ecosystem of the Caéte Bay, Northeast Pará, Brazil [Elektronische Ressource] / vorgelegt von Kerstin Kober

Kerstin Reinemann

Informations

• Publié par: universitat_bremen
• Publié le: 01 janvier 2004
• Nombre de lectures: 18
• Langue: Deutsch
• Poids de l'ouvrage: 2 Mo

Extrait

Foraging ecology and habitat use of wading birds
and shorebirds in the mangrove ecosystem of the
Caéte Bay, Northeast Pará, Brazil


Dissertation
zur Erlangung des Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.)


Angefertigt am
Zentrum für Marine Tropenökologie
des Fachbereiches 2 der Universität Bremen
Bremen

und am
Institut für Vogelforschung
„Vogelwarte Helgoland“
Wilhelmshaven

vorgelegt von
Kerstin Kober

Bremen 2004





























Tag des öffentlichen Kolloquiums: 27.07.2004

Gutacher der Dissertation:
Prof. Dr. Ulrich Saint-Paul
Prof. Dr. Franz Bairlein
































Diese Dissertation wurde mit Hilfe einer Promotionsförderung der Konrad-Adenauer Stiftung
(Begabtenförderung) und eines “DAAD Doktorandenstipendiums im Rahmen des
gemeinsamen Hochschulsonderprogramms III von Bund und Ländern” des DAAD erstellt. Contents
Contents
CONTENTS
ABBREVIATION LIST
SUMMARY
RESUMO
ZUSAMMENFASSUNG

1 GENERAL INTRODUCTION ............................................................................................1
2 MATERIALS AND METHODS..........................................................................................6
2.1 STUDY AREA AND SAMPLING SITES ...............................................................................6
2.2 STUDY DESIGN ..........................................................................................................10
2.2.1 Environmental conditions and the benthic community .................................................. 11
2.2.2 Avian community ........................................................................................................... 15
2.2.3 Exclosures ..................................................................................................................... 21
2.3 STATISTICAL ANALYSIS ..............................................................................................24
2.3.1 Data preparation............................................................................................................ 24
2.3.2 Univariate statistical methods........................................................................................ 25
2.3.3 Multivariate statistical methods/Ordination.................................................................... 25
3 THE TROPICAL TIDAL FLATS – ENVIRONMENTAL CONDITIONS AND THE
BENTHIC COMMUNITY .................................................................................................29
3.1 INTRODUCTION ..........................................................................................................29
3.2 RESULTS...................................................................................................................30
3.2.1 Sediment........................................................................................................................30
3.2.2 Salinity.... 31
3.2.3 Time of emergence........................................................................................................ 32
3.2.4 The macrobenthic community – availability of prey organisms for the birds................. 32
3.3 DISCUSSION ..............................................................................................................48
4 MIGRANT MEETS RESIDENT – DISTRIBUTION AND STRUCTURE OF THE AVIAN
COMMUNITY ..................................................................................................................54
4.1 INTRODUCTION ..........................................................................................................54
4.2 RESULTS...................................................................................................................55
4.2.1 Taxonomic composition................................................................................................. 55
4.2.2 Abundances 58
4.2.3 Spatial distribution ......................................................................................................... 59
4.2.4 Guilds............................................................................................................................. 64
4.3 DISCUSSION ..............................................................................................................67 Contents
5 FORAGING AT TROPICAL TIDAL FLATS – BIRDS IN RELATION TO THE BENTHIC
COMMUNITY ..................................................................................................................72
5.1 INTRODUCTION ..........................................................................................................72
5.2 RESULTS...................................................................................................................74
5.2.1 Harvestable prey fraction............................................................................................... 74
5.2.2 Diet ................................................................................................................................ 77
5.2.3 Distribution of birds in relation to macrobenthos ........................................................... 83
5.3 DISCUSSION ..............................................................................................................89
6 AVIAN CONSUMPTION AND FORAGING BEHAVIOUR..............................................96
6.1 INTRODUCTION ..........................................................................................................96
6.2 RESULTS...................................................................................................................97
6.2.1 Time budgets................................................................................................................. 97
6.2.2 Calculated consumption .............................................................................................. 101
6.2.3 Exclosures 106
6.2.4 Behaviour..................................................................................................................... 109
6.3 DISCUSSION ............................................................................................................114
7 REFERENCES..............................................................................................................126
8 ACKNOWLEDGEMENTS.............................................................................................139
9 LIST OF FIGURES........................................................................................................140
10 LIST OF TABLES .........................................................................................................143
11 APPENDICES ...............................................................................................................147
11.1 APPENDIX I: METHODS.........................................................................................147
11.2 APPENDIX II: ENVIRONMENTAL CONDITIONS AND THE BENTHIC COMMUNITY............152
11.3 APPENDIX III: DISTRIBUTION AND STRUCTURE OF THE AVIAN COMMUNITY...............164
11.4 APPENDIX IV: THE BIRDS IN RELATION TO THE BENTHIC COMMUNITY ......................169
11.5 APPENDIX V: AVIAN CONSUMPTION AND FORAGING BEHAVIOUR.............................177 Abbreveation list
Abbreveation list
In some instances, for example in some figures, the use of the full names and expressions
was not possible or practical. In these cases short forms were used, which are listed below:

Bird names Study areas
Collared Plover copl Furo Grande FG
Great Egret greg Furo do Chato FC
Grey Plover grpl Ilha de Canelas C
Greater Yellowlegs grye
Little Blue Heron lbhe Experimental treatments
Marbled Godwit mago Exclosures Ex
Red Knot knot Control C
Ruddy Turnstone turn Procedural Control PC
Sanderling sand
Short-billed Dowitcher sbdo
Scarlet Ibis scib Others
Spotted Sandpiper sdsa Gross food intake GFI
Snowy Egret sneg Ash free dry weight AFDW
Semipalmated Plover sppl
Semipalmated Sandpiper spsa
Tricolored Heron tche
Whimbrel whim
Willet will
Yellow-crowned Nightheron ycnh

Summary
Summary
Only little is known of wintering and resting shorebirds in tropical environments. The objective
of this thesis was to describe the environment and the food availability the birds encounter in
the tropics, the bird community in this habitat, the relationship between birds and
environment/prey and the effects of bird consumption at tropical tidal flats. The study was
conducted at the Bragantinian peninsula in the Northeast of Brazil, an area previously
characterized as of major importance for migratory shorebirds.
The study area was a poor and very variable foraging habitat, comprising an overall low
content of organic material, many physical disturbances and high fluctuations of sediment