BIRDS CROSSING BORDERS: A POPULATION STUDY OF ARCTIC TERNS

304 Pages·2012·2.17 MB·English

BIRDS CROSSING BORDERS: A POPULATION STUDY OF
ARCTIC TERNS (STERNA PARADISAEA)

by

Catherine M. Devlin

B.A. Human Ecology, College of the Atlantic, 1993
M.Sc. Ecology and Evolution, Rutgers the State University of New Jersey, 1997

A Dissertation Submitted in Partial Fulfilment of
the Requirements for the Degree of

Doctor of Philosophy

in Biology

Supervisor: Antony W. Diamond, PhD, Biology and Forestry and
Environmental Management

Examining Board: Graham J. Forbes, PhD, Biology and Forestry and
Environmental Management, Chair
Stephen B. Heard, PhD, Biology
Tom Beckley, PhD, Forestry and Environmental
Management

External Examiner: Emmanuelle Cam, PhD, Laboratoire Évolution et
Diversité Biologique (EDB), Université Paul
Sabatier, Toulouse III (UPS), France

This dissertation is accepted by the
Dean of Graduate Studies

THE UNIVERSITY OF NEW BRUNSWICK

November, 2005

© Catherine M. Devlin, 2006
Dedication
I dedicate this dissertation to all of you who have had your vision obscured by the
beating of a thousand tern wings, have had your ears filled with their boisterous incessant
calls, have held a pipping egg to your ear and a downy chick in your hand, and have had
the reverie of island life broken by a sharp thwack on the head from a beak to remind you
that even though you are working in their interest, you are only a visitor in their world.
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Abstract
The Gulf of Maine offers a unique opportunity to examine the population
dynamics of seabirds at a metapopulation scale. Approximately half of the estimated
12,800 pairs of Arctic Terns breeding in eastern North America nest in the Gulf of Maine
and over 90% of these pairs nest on only four islands. Building on existing monitoring
programs and recognizing that terns, like many species, do not recognize political
boundaries, this study established a long-term project to fill gaps in the understanding of
the population dynamics of Arctic Terns, using 1953 adults and 3891 chicks banded and
observed on four islands in the Gulf of Maine between 1999 and 2003.
Two discriminant functions identified the head-bill and bill depth of adults as the
best measurements to separate the sexes. These functions correctly classified 73-74% of
terns. A non-linear equation fitted through a plot of the probability of classifying an
individual and the discriminant scores provides a way for researchers to calculate the
probability of sexing any Arctic Tern.
Approximately 50% of adults and 8% of chicks banded on Machias Seal Island
(MSI), Petit Manan Island (PMI), Seal Island (SI) and Matinicus Rock (MR) were re-
encountered. Probability of re-encountering adults ranged from 0.16-0.74, depended on
year and colony, and was generally highest on Matinicus Rock. Probability of re-
encountering terns banded as chicks ranged from 0.003-0.336, depended on age and
colony, and was highest for 4-year olds from Seal Island. The probability of survival for
adults when controlled for transient individuals was 0.77 (SE=0.028) the first year
following banding and 0.97 (SE=0.027) for subsequent years. Probability of survival for
terns banded as chicks was age-specific ranging from 0.55 (SE=0.189) from fledging to
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1-year and 0.83 (SE=0.181) for those terns > 1 year old. Mean age of first breeding for
109 terns was 2.8 yrs (SE=0.08). Probability of breeding dispersal ranged from 0.0-
0.025; emigration was highest from PMI. Probability of natal dispersal ranged from
0.01-0.07; emigration was highest from MR. A population viability analysis indicated
that current trends in productivity, survival and dispersal may lead to the doubling of the
regional tern population within 50 years.

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Acknowledgments
This work was funded by the Atlantic Cooperative Wildlife Ecology Research Network
(ACWERN), the Canadian Wildlife Service, the U.S. Fish and Wildlife Service, the
National Audubon Society‟s Seabird Restoration Program, the Sir James Dunn Wildlife
Research Centre at the University of New Brunswick, and the Ecological Monitoring and
Assessment Network.

I thank my dedicated and hard-working supervisor, Tony Diamond, the Diamond
ACWERN Lab and the larger ACWERN community, my supervisory and examining
committees, the Saunders and Clark genetics Labs, the Department of Biology and others
at the University of New Brunswick, the Canadian Wildlife Service (especially those in
the Atlantic Region), the U.S. Fish and Wildlife Service (especially the Maine Coastal
Islands National Wildlife Refuge), the National Audubon Society‟s Seabird Restoration
Program and Project Puffin, the U.S.G.S. Patuxent Wildlife Research Center, the
Lighthouse Keepers and all those involved with the guardianship of Machias Seal Island,
and all members (past and present) of the Gulf of Maine Seabird Working Group and the
Atlantic Canada Tern Working Group.

I whole heartedly thank each and every one who has been involved in supporting this
work. I thank all those who gave advice in the planning, collaboration, data collection,
analysis, writing and presentation stages, the boat captains who made sure that everyone
arrived at and returned from the islands safely, the birds, and the many field assistants
and island supervisors who helped collect data and made this work possible; I thank my
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family for their love, encouragement and endless patience; and lastly I thank everyone
who wrote a tune or shared a tune, a story, a paper, a book, made me laugh, gave me a
kick and encouraged me to continue with this work.
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Table of Contents
Dedication ........................................................................................................................... i
Abstract .............................................................................................................................. ii
Acknowledgments ............................................................................................................ iv
List of Tables .................................................................................................................... xi
List of Figures ................................................................................................................ xvii
1.0 Birds Crossing Borders: Metapopulation Study of Arctic Terns .......................... 1
1.1 Introduction .................................................................................................................. 1
1.2 Background and Population Biology Context ............................................................. 3
1.2.1 Seabird Life History and Demography ......................................................... 3
1.2.2 Metapopulations ............................................................................................ 5
1.2.3 Capture-Mark-Recapture / Re-encounter .................................................... 10
1.2.4 Population Viability Analysis ..................................................................... 11
1.3 Study Species: Arctic Terns ....................................................................................... 13
1.3.1 Distribution and Status ................................................................................ 14
1.3.2 Life History ................................................................................................. 15
1.4 Objectives .................................................................................................................. 16
1.5 Study Location and Historical Populations................................................................ 18
1.5.1 Machias Seal Island .................................................................................... 19
1.5.2 Petit Manan Island ...................................................................................... 20
1.5.3 Seal Island ................................................................................................... 21
1.5.4 Matinicus Rock ........................................................................................... 22
1.6 Overview of Chapters ................................................................................................ 23
1.7 Literature Cited .......................................................................................................... 24
2.0 Sexing Arctic Terns in the field and laboratory .................................................... 47
2.1 Abstract ...................................................................................................................... 48
2.2 Introduction ............................................................................................................... 49
2.3 Methods...................................................................................................................... 50
2.4 Results ........................................................................................................................ 53
2.5 Discussion .................................................................................................................. 56
2.6 Acknowledgements .................................................................................................... 59
2.7 Literature Cited .......................................................................................................... 60
2.8 Addendum .................................................................................................................. 66
2.8.1 Literature Cited ........................................................................................... 67
3.0 Metapopulation analysis of the survival and breeding dispersal of adult
Arctic Terns nesting in the Gulf of Maine ........................................................ 69
3.1 Abstract ...................................................................................................................... 70
3.2 Introduction ............................................................................................................... 71
3.2.1 Metapopulation Dynamics .......................................................................... 71
3.2.2 Study Goals ................................................................................................. 73
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3.2.3 Hypotheses and Predictions ........................................................................ 73
3.2.3.1 Survival and Probability of Re-encounter ........................................... 73
3.2.3.2 Breeding Dispersal ............................................................................... 74
3.2.3.3 Sex, Survival and Breeding Dispersal ................................................. 76
3.3 Methods...................................................................................................................... 76
3.3.1 Study area.................................................................................................... 76
3.3.2 Field methods .............................................................................................. 77
3.3.2.1 Trapping and Banding ......................................................................... 77
3.3.2.2 Re-Encounters ...................................................................................... 78
3.3.2.3 Nest Monitoring ................................................................................... 78
3.3.3 Analytical Modeling Methods .................................................................... 79
3.3.3.1 Encounter Histories and Parameter Definitions ................................... 79
3.3.3.2 Models ................................................................................................. 80
3.3.3.2.1 Global Model ................................................................................ 80
3.3.3.2.2 Model Set A (Survival Parameter, S) ............................................ 81
3.3.3.2.3 Model Set B (Re-encounter Parameter, p) .................................... 82
3.3.3.2.4 Model Set C (Covariates to Movement, ψ) ................................... 82
3.3.3.2.5 Sex, Survival and Breeding Dispersal........................................... 83
3.3.3.3 Multi-site Model Assumptions ............................................................ 83
3.3.3.4 Goodness of Fit .................................................................................... 85
3.3.3.5 Model Selection ................................................................................... 87
3.4 Results ........................................................................................................................ 89
3.4.1 Field Results................................................................................................ 89
3.4.1.1 Trapping and Banding ...................................................................... 89
3.4.1.2 Re-encounters ...................................................................................... 89
3.4.1.3 Nest Monitoring ................................................................................... 90
3.4.2 Modeling Results ........................................................................................ 91
3.4.2.1 Parameter Estimates ............................................................................. 92
3.5 Discussion .................................................................................................................. 93
3.5.1 Survival ....................................................................................................... 94
3.5.2 Re-encounter probability ............................................................................ 96
3.5.3 Breeding Dispersal ...................................................................................... 98
3.5.4 Conclusion ................................................................................................ 101
3.6 Acknowledgements .................................................................................................. 102
3.7 Literature Cited ........................................................................................................ 102
4.0 Survival and dispersal of Arctic Terns banded as chicks in the Gulf of
Maine .................................................................................................................. 123
4.1 Abstract .................................................................................................................... 124
4.2 Introduction .............................................................................................................. 125
4.2.1 Study Goals ............................................................................................... 126
4.2.2 Hypotheses and Predictions ...................................................................... 126
4.2.3.1 Survival and Probability of Re-encounter ......................................... 126
4.2.3.2 Age of first breeding .......................................................................... 127
4.2.3.3 Dispersal ............................................................................................ 128
4.3 Methods.................................................................................................................... 129
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4.3.1 Study Area ................................................................................................ 129
4.3.2 Field Methods ........................................................................................... 130
4.3.2.1 Nest Monitoring and Banding ............................................................ 130
4.3.2.2 Re-encountering Banded Birds and Age of First Breeding ............... 131
4.3.3 Analytical Methods ................................................................................... 131
4.3.3.1 Encounter Histories and Parameters .................................................. 131
4.3.3.2 Models ............................................................................................... 132
4.3.3.2.1 Model Set A (Survival Probability, S) ........................................ 134
4.3.3.2.2 Model Set B (Re-encounter Probability, p) ................................ 134
4.3.3.2.3 Model Set C (Covariates to Movement, ψ) ................................. 134
4.3.3.3 Multi-site Model Assumptions .......................................................... 135
4.3.3.4 Goodness of Fit .................................................................................. 137
4.3.3.5 Model Selection ................................................................................. 137
4.4 Results ...................................................................................................................... 137
4.4.1 Field Results.............................................................................................. 137
4.4.1.1 Nest Monitoring ................................................................................. 137
4.4.1.2 Banding and Re-encountering Banded Birds ..................................... 138
4.4.1.3 Age of First Breeding ........................................................................ 138
4.4.2 Modeling Results ...................................................................................... 139
4.4.2.1 Parameter Estimates ............................................................................ 140
4.5 Discussion ................................................................................................................ 140
4.5.1 Survival ..................................................................................................... 142
4.5.2 Re-encounter and Age of First Breeding .................................................. 143
4.5.3 Dispersal ................................................................................................... 145
4.5.4 Conclusion ................................................................................................ 148
4.6 Acknowledgements .................................................................................................. 148
4.7 Literature Cited ........................................................................................................ 149
5.0 Population Viability Analysis of Arctic Terns Nesting in the Gulf of
Maine .................................................................................................................. 169
5.1 Abstract .................................................................................................................... 170
5.2 Introduction .............................................................................................................. 171
5.2.2 Study Goals ............................................................................................... 173
5.3 Methods.................................................................................................................... 174
5.3.1 Modeling Approach .................................................................................. 174
5.3.2 Geographic Limits and Spatial Structure .................................................. 175
5.3.3 Population Demographics ......................................................................... 176
5.3.3.1 Stage Matrix ....................................................................................... 176
5.3.3.2 Maternity ............................................................................................ 177
5.3.3.3 Age at First Breeding ......................................................................... 178
5.3.3.4 Survival .............................................................................................. 179
5.3.4 Demographic and Environmental Stochasticity........................................ 179
5.3.4.1 Catastrophe 1: Reproductive Failure ................................................. 180
5.3.4.2 Catastrophe 2: Increased Adult Mortality .......................................... 181
5.3.5 Initial Abundances and Age Distribution ................................................. 182
5.3.6 Density Dependence ................................................................................. 182
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5.3.7 Dispersal ................................................................................................... 183
5.3.7. Dispersal-distance relationship ............................................................ 184
5.3.7.2 Density dependence in dispersal ........................................................ 184
5.3.8 Spatial Correlations ................................................................................... 185
5.3.9 Management Actions ................................................................................ 185
5.3.10 Simulations ............................................................................................. 186
5.4 Results ...................................................................................................................... 186
5.4.1 Metapopulation Viability and Model Sensitivity to Uncertainty .............. 186
5.4.2 Effect of decreased reproductive success (Catastrophe 1) ........................ 188
5.4.3 Effect of increased mortality (Catastrophe 2) ........................................... 188
5.5 Discussion ................................................................................................................ 188
5.5.1 Philopatry and Dispersal ........................................................................... 190
5.5.1.1 Population Increase ............................................................................ 191
5.5.1.2 Habitat Stability ................................................................................. 192
5.5.1.3 Disturbance ........................................................................................ 194
5.5.2 Density Dependence ................................................................................. 195
5.6 Conclusion ............................................................................................................... 197
5.7 Acknowledgements .................................................................................................. 198
5.8 Literature Cited ........................................................................................................ 199
6.0 General Discussion and Significance of Study .................................................... 230
6.1 Sexing Birds ............................................................................................................. 230
6.2 Survival .................................................................................................................... 231
6.3 Documenting Dispersal ............................................................................................ 233
6.3.1 Breeding Dispersal .................................................................................... 234
6.3.2 Natal Dispersal .......................................................................................... 235
6.4 Population Viability Analysis .................................................................................. 237
6.6 Suggestions For The Future ..................................................................................... 238
6.6.1 Research Protocol ..................................................................................... 239
6.6.2 Genetics..................................................................................................... 240
6.7 Conclusion ............................................................................................................... 240
6.8 Literature Cited ........................................................................................................ 242
Appendices ..................................................................................................................... 250
Appendix I: Permission to reprint article .................................................................. 251
Appendix II. Protocol for Arctic Tern Metapopulation Study ................................ 252
II.I Trapping and Banding Arctic Terns ........................................................................ 252
II.I.I Nesting Phenology ..................................................................................... 252
II.I.II Timing of Trapping .................................................................................. 254
II.I.III Trap Type and Method of Trapping........................................................ 254
II.I.IV How long to trap ..................................................................................... 256
II.I.V Weather .................................................................................................... 257
II.I.VI Whom To Trap? ...................................................................................... 258
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