Social dominance can influence the allocation of resources in animal groups and
has important consequences for individual fitness. In my thesis, I examined the
structure, formation, maintenance and consequences of dominance, in the
cooperatively breeding pukeko (Porphyrio melanotus melantous: Aves). I first
describe a quantitative analysis of pukeko dominance networks (Chapter 2),
which included one of the first applications of exponential random graph models
in behavioural ecology. This study demonstrated that pukeko form highly ordered
dominance hierarchies, and that dominance relationships were influenced by
both the attributes of individual birds, as well as self-organizational processes
such as winner and loser effects. Additionally, I demonstrated that hatching order
has an important influence on the formation of dominance relationships, with
earlier hatched chicks achieving higher dominance ranks as adults (Chapter 3).
To maintain dominance relationships, pukeko use their red frontal shield as a
‘status signal’, with larger frontal shields indicating more dominant individuals. I
showed that sexual dimorphism in frontal shield size is dramatically different in
two pukeko populations, probably due to differences in the intensity of intrasexual
competition (Chapter 4). Furthermore, by manipulating apparent frontal shield
size, I demonstrated that shield phenotype both influences, and is influenced by,
social interactions (Chapter 5). This bi-directional relationship between signals
and social interactions challenges conventional signalling theory, and has
important implications for how honesty is maintained in this signalling system. Finally, I expanded my findings on pukeko colour traits by exploring interspecific
patterns of bill colouration in over 1600 bird species (Chapter 6). This study
revealed that colourful bills likely evolved as a signal used in competitive
interactions, rather than as a sexual signal. Taken together, my research
provides a significant advancement in our understanding of the complex nature of
dominance in a wild bird, and provides both a methodological and theoretical
basis for future studies on animal social behaviour. / Thesis / Doctor of Science (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/17407 |
| Date | 06 1900 |
| Creators | Dey, Cody |
| Contributors | Quinn, James, Balshine, Sigal, Biology |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
Page generated in 0.0018 seconds