Abstract:
This thesis focuses on a behavioural and ecological study of adult males of the endemic damselfly species Xanthocnemis zealandica (redcoat damselfly) at the Auckland Botanic Gardens, Manurewa, New Zealand. For this, three related topics are addressed: (1) population density over the summer and its relationship with environmental data; (2) male focal observations to assess the range and frequency of their behaviour; and (3) male territoriality and agonistic behaviour. The first topic assessed adult damselfly populations over twelve weeks between January and May of 2013, taking measurements of average wind speed, air temperature, humidity, pH, water temperature, turbidity, coordinates, altitude, and water depth at three different points in five ponds at the Auckland Botanic Gardens. Scans at each point were performed recording the number of males, females, couples in tandem position, couples ovipositing, couples in wheel position, and agonistic encounters. The second topic was achieved using 30 minute focal observations for 60 individuals recording all the behaviours performed during this period. From the focal observations, agonistic interactions were taken and compared relative and absolute size between owners and intruders to link with the third topic of agonistic behaviour. Results from the scans showed that there is a change over time in the number of individuals, couples, and agonistic interactions. Results from the environmental data show that air temperature was the best predictor for the number of individuals; however, humidity, pH and water temperature were also highly correlated with the number of individuals. From focal observations, males spend most of their time perching, and there were significant differences between males and females regarding wing length. In addition, there was a correlation between the number of individuals and the number of couples and agonistic interactions. The results from agonistic behaviour observations indicated that territory +-owners tend to win contests against intruders, and that relative size and absolute size play no role in the outcome or duration of agonistic encounters. Overall, this thesis contributes to our knowledge of damselflies in New Zealand and to our broader understanding of the processes influencing male behaviour and territoriality