Mating system variation in relation to disease biology in Charadrius plovers

: (Alternative Format Thesis)

Abstract

The study of social behaviours has been exuberant given the broad facets that it encompasses, from the social environment and sexual selection to mating behaviour and parental care. Social behaviours, especially mating and parenting behaviours, are highly variable and are associated with fitness-related processes in wild populations. An increasingly important element of social behaviour is the transmission dynamics of pathogens within and between social groups. Therefore, understanding how social behaviours impact the prevalence of disease in wild populations is an essential objective both in evolutionary biology and wildlife disease biology. The general objective of my dissertation is to explore the mating decision process and its implications in the prevalence of disease infections in Charadrius plover, a group of shorebirds with remarkable variation in breeding behaviours. Using empirical and theoretical modelling approaches, my PhD provided three novel insights. First, as evolutionary theory predicts that, in species that form pair-bonds, successful reproduction should lead to retention of the breeding pair for future reproduction. However, by investigating a polygamous plover population, I found the contrary since successful breeding promoted divorce, whereas failed breeding resulted in mate retention (Chapter 2). To check the generality of the latter results, I carried out a comparative study of 14 plover populations (Chapter 3): the result supported my previous finding, suggesting that plovers commonly benefit by mating with a new partner and reproduce shortly after divorce. Second, by using theoretical model, I showed how population sex ratio and disease characteristics drive the prevalence of sexually transmitted infections in males and females (Chapter 4). Third, I quantified composition of gut bacteria in two wild populations of plovers (Chapter 5) and showed that the gut microbial diversity is predicted by local environment rather than population social structures (i.e. age or sex of plovers). Taken together, my discoveries uncovered fundamental relationships between mating systems, population demography and disease prevalence using wild bird populations as model organisms. Given the significance of diseases in population demography of social human and nonhuman populations, further research needed to uncover how social structure impacts spread of diseases, and vice versa, how diseases impact on social structures.

Date of Award	20 Jan 2021
Original language	English
Awarding Institution	University of Bath
Sponsors	China Scholarship Council
Supervisor	Tamas Szekely (Supervisor), Ben Ashby (Supervisor) & Richard James (Supervisor)