Individual fitness correlates in consecutive years of pair bond in Upland Geese [Elektronische Ressource] / Anja Gladbach. Betreuer: Bart Kempenaers

Anja Gladbach

Informations

• Publié par: ludwig-maximilians-universitat_munchen
• Publié le: 01 janvier 2011
• Nombre de lectures: 9
• Langue: English
• Poids de l'ouvrage: 23 Mo

Extrait

INDIVIDUAL FITNESS CORRELATES IN
CONSECUTIVE YEARS OF PAIR BOND IN
UPLAND GEESE












DISSERTATION



Fakultät für Biologie
Ludwig-Maximilians-Universität München



durchgeführt am
Max-Planck-Institut für Ornithologie
Seewiesen & Vogelwarte Radolfzell



vorgelegt von

Anja Gladbach, geb. Kahles

März 2011 Erstgutachten: Prof. Dr. Bart Kempenaers
Zweitgutachten: Prof. Dr. Volker Witte

Tag der Abgabe: 30.03.2011
Tag der mündlichen Prüfung: 01.08.2011 “Sometimes, if you stand on the bottom rail of
a bridge and lean over to watch the river
slipping slowly away beneath you, you will
suddenly know everything there is to be
known.“
Winnie the Pooh CONTENTS


CHAPTER 1 General Introduction………………………………………… 7
Outline……………………………………………………… 11

CHAPTER 2 The Upland goose……………………………………………. 13
New Island…………………………………………………... 17
Methods……………………………………………………... 18

CHAPTER 3 Seasonal clutch size decline and individual variation in the
timing of breeding are related to female body condition in a
non-migratory species, the Upland Goose Chloephaga
picta leucoptera ………………………………………………… 21

CHAPTER 4 Variations in leucocyte profiles and plasma biochemistry
are related to different aspects of parental investment in
male and female Upland geese Chloephaga picta
leucoptera………………………………………………………… 33

CHAPTER 5 Can faecal glucocorticoid metabolites be used to monitor
body condition in wild Upland geese Chloephaga picta
leucoptera? ………………………………………………………. 45

CHAPTER 6 Female-specific colouration, carotenoids and reproductive
investment in a dichromatic species, the Upland goose
Chloephaga picta leucoptera……………………...…………… 55

CHAPTER 7 Male achromatic wing colouration is related to body
condition and female reproductive investment in a
dichromatic species, the Upland goose Chloephaga picta
leucoptera……………………………………………………. 69

CHAPTER 8 General discussion………………………………………… .. 79
Summary……………………………………………………. 86
Zusammenfassung……………………………………………. 88
References………………………………………………… .. 90
Acknowledgements…………………………………………. 92
Curriculum vitae……………………………………………. 94
Declaration………………………………………………….. 98 ONE
General introduction CHAPTER 1 - GENERAL INTRODUCTION 9
and between-individual variation is consistent GENERAL INTRODUCTION
or highly repeatable over time.
To explain, why a certain species is what it is Selection acts upon the phenotype of
and lives where it does, it is necessary to organisms, i.e. any observable characteristic or
understand the evolutionary processes that lead trait (morphology, development, biochemical
to its current appearance and distribution. In or physiological properties, behaviour and
this thesis I describe a variety of individual products of behaviour). The phenotype of an
characters and their relation to fitness in both individual results from the expression of its
males and females in a population of wild inherited genes and the influence of
Upland geese (Chloephaga picta leucoptera) environmental and developmental factors.
on the Falkland Islands. Phenotypic differences between individuals
within a population that are correlated with
Natural and sexual selection fitness can indicate which selection pressures
Individuals will survive, reproduce and leave are currently working or have been working in
the past. We thereby can try to explain which different numbers of descendants, depending
upon how well they are adapted to current selective forces led to the current appearance
environmental conditions. In this sense, some and behaviour of individuals. Knowledge
about fitness correlates can be used to manage individuals are fitter than others; they make a
greater contribution to the gene pool of the populations or to predict the potential impact
next generation. Traits that increase the fitness of changes in environmental conditions due to
of an individual are selected for, others that natural or anthropogenic causes.
decrease fitness are selected against and traits
that neither increase nor decrease fitness are Only heritable traits can evolve through
selectively neutral (Fisher 1930). The change selection
of heritable characteristics of a population The determination of fitness correlates in field
during the course of time is called evolution by studies is only the first step to understand how
natural selection. This concept was first selection may have worked in a particular
published by Darwin in 1859 and later refined species. After the description of phenotypic
by introducing sexual selection as a special differences that are related to variations in
process shaping mechanisms that function fitness, it is necessary to investigate whether
shortly before or at the time of mating and these traits could have been shaped by
selection. As only selection acting on the serve in the process of obtaining mates
(Darwin 1871). Darwin regarded it basically genetic component of a trait will lead to an
different from most forms of natural selection evolutionary response (Kruuk 2004), while
selection on the nonheritable environmental in that it does not increase survival but
reproductive success of individuals. Using component of the phenotype will not (Price et
Darwin’s own words, sexual selection can be al. 1988; Rausher 1992), selection can only
divided into two distinct processes, “the power optimize traits that are heritable.
to charm the females” (intersexual selection), Heritability is defined as the
and “the power to conquer other males in proportion of total phenotypic variation due to
battle” (intrasexual selection). Today it is all genetic effects. Detecting the heritability of
acknowledged that both natural and sexual traits in field studies is not always easy. One
selection are just different aspects of one method we used in this study is to look at the
process, because both survival and repeatability of measured characters.
reproductive success influence the lifetime Repeatability is the proportion of phenotypic output and thereby fitness of variation that can be attributed to between-
individuals. subject (or between-group) variation and an
important index for quantifying the accuracy of
Phenotypic variation - the basis for selection measurements and the constancy of
For both natural and sexual selection to work, phenotypes (Lessells and Boag 1987). Whereas
inter-individual variation is fundamental. This heritability indicates purely genetic
can be caused by mutation, recombination and differences, the repeatability index
gene flow between populations. A specific trait incorporates both genetic and environmental
in a population can evolve through selection sources of variation. It is assumed to set the
only if the variations affect individual fitness approximate upper limit for heritability
(Falconer and Mackay 1996; Dohm 2002) 10 CHAPTER 1 - GENERAL INTRODUCTION
Traits that show high inter-individual variation stable social monogamous pair bonds over
and high repeatability levels could have several years and show a strong sexual
potentially evolved through natural or sexual dimorphism in both size and colouration, a
selection. combination underrepresented in the current
literature. In this thesis I describe the
Why study fitness correlates in Upland relationship of several morphological and
geese? physiological traits to aspects of fitness in both
Studies of selection in the wild have males and females of this species.
continually increased since Darwin (1859)
introduced his theory 150 years ago. A first Table 2. Summary of the selection database in
review of field studies was published by Siepielski et al. (2009) – Table adapted
Endler in his influential book ‘Natural Number of items in the
database selection in the wild’ (1986). Two more recent
reviews by Kingsolver (2001) and Siepielski et Studies 89
al. (2009) both found a very similar strength of Selection coefficients 5519
selection on traits (averaged over years within Linear differentials 1989
a dataset) and give an up-to-date overview Linear gradients 1989
over selection studies. Despite the large Quadratic differentials 776
number of studies that can be found for birds,
Quadratic gradients 765
there is a considerable bias towards studies in
Species 73
Passeriformes and species with a socially
Genera 61 monogamous mating system with seasonally
Taxon type changing partners (Table 1). Also, most studies
Invertebrates 482 (studies = 13) concentrate on morphology and life history,
Plants 365 (studies = 28) while studies focussing on selection on
physiological traits are still missing (Table 2). Vertebrates 2567 (studies = 48)
Total types of selection
Sexual selection 512 Table 1. Studies on selection in wild bird
populations included in recent reviews. Natural selection 2902
Kingsolver Siepielski Trait type
(2001) (2009)
Behavioural 21
Order
Life history 1244
Passeriformes 1