Behavioural responses to anthropogenic disturbances

When a habitat undergoes change, the first response of an individual is often behavioural adjustment. This immediate response can determine whether the population will survive or not, as behavioural flexibility gives time for genetic changes to arise later on. Habitat changes that alter reproductive behaviours can have long-lasting effects on populations. If the selective regime has changed under the new conditions, mate choice cues may no longer reliably reflect an individual s quality. Thus, animals have to be able to adjust their reproductive behaviours to the local conditions. The aim of my thesis was to discuss if and how animals are able to respond to rapid anthropogenic environmental change, and to study the mechanisms of the responses and the evolutionary consequences. The main focus was on the effects of human-induced eutrophication on the reproductive behaviour of fishes. Eutrophication is the result of increased nutrient input and can cause dense underwater vegetation and algal blooms. I used fishes from two very different ecosystems as model species, the Baltic Sea threespine stickleback (Gasterosteus aculeatus) and the desert goby (Chlamydogobius eremius), an endemic species of the Lake Eyre region in Central Australia. I investigated the effects of increased habitat complexity on courtship behaviour and the possibility of local differentiation in courtship and nest building behaviour depending on the level eutrophication in the habitat of origin. Furthermore, I observed the effect of turbidity on stickleback nest building behaviour. The results show that threespine stickleback males, which were born in areas that have been eutrophied for decades, court females at a higher intensity than males from clear water areas. Similarly, male desert gobies increased their courtship effort in dense vegetation. Intense courtship could be an adjustment to reduced visibility and lowered predation risk in the densely vegetated sites. However, there were no clear differences in nest building between males from clear and eutrophied areas under standardized conditions. This was expected as Baltic Sea sticklebacks prefer to nest under vegetation cover and are fairly rigid in adjusting their nest characteristics. Nest building was affected by increased turbidity: males built smaller nests with a larger nest entrance in turbid water. The large variation in the magnitude of phytoplankton blooms may require a rapid adjustment of the optimal nest structure to the current conditions. This thesis highlights the complex interactions that are set- off by human-induced changes in habitats and are followed by the immediate behavioural responses. It also encourages more research to tease apart the phenotypic and genetic components of the observed behavioural differences.

The Role of Electronic Word of Mouth in Shaping Consumer Attitudes

The purpose of this research was to investigate the role of electronic word of mouth (eWOM) in shaping consumer attitudes towards various products and services with concentration on the consumer attitude change. eWOM has long been proven to play an important role in influencing consumer attitudes and has been researched from a variety of perspectives. This study attempts to look deeper into the process of consumer attitude change by applying as the central theory of the study the Elaboration Likelihood Model of Persuasion by Petty and Cacioppo. In the processes of examining the background academic and empirical research the Internet and Web 2.0 are closely depicted in order to understand how throughout the past centuries technology allowed the rise of various mediums where consumers can not only share their opinions online about products and services but also communicate with other consumers. Manuel Castel’s Internet Galaxy, Gildin’s, Carl and Noland’s, Hennig-Thurau, Gwinner, Walsh and Gremler’s researches on eWOM are the central works that helped to shape both the theoretical and empirical parts of this study. The mixed method approach was chosen as a research method for this study. An online survey was conducted via the Surveymonkey.com platform and eight qualitative in-depth interviews were conducted. The results of the study show that central route queues as text quality and text argumentativeness are more prominent among the research subjects and the peripheral route queues: source credibility and source expertise did not show considerable significance. Also more experience and participation consumers have with user-rating websites and applications more inclined they are to elaborate on the central route cues and are more likely to search for opinions that they consider rational and credible. Also these respondents are less inclined to search for ratings that confirm their existing beliefs about products or services. Less experience/participation they have about eWOM more likely they are to search for reviews confirmatory to their own.