In the past decades a growing number of studies have shown that wind power development have detrimental effects on bats. Meanwhile, data on insect abundance and communities in wind farms are lacking, making it challenging to successfully predict the effects of wind power on insect populations. As a way of addressing this knowledge gap, the aim of this thesis was to quantify insect abundance, size groups and identify insect orders present in a wind farm situated in southwest Norway. Moreover, I investigated whether insect abundance had an influence on bat activity in the wind farm, and if elevation and distance to freshwater had an effect on insect abundance. Insects were collected from below the base of seven existing wind turbines in Stigafjellet Wind Farm, Rogaland. Individuals were counted, identified to order level and grouped in size categories based on bat prey size preferences. Nightly bat activity and feeding behaviour were recorded using ultrasonic acoustic detectors. I found that insect abundance varied considerably across the study site, and that small flying insects were the most abundant throughout the wind farm. Statistical modelling revealed that turbine elevation had a positive effect on insect abundance, while distance to freshwater had a weak, negative effect on insect abundance. From the collected samples, I identified seven orders of flying insects, with orders Diptera and Hymenoptera being the most abundant. Overall bat activity and bat foraging activity varied greatly throughout the monitoring period, and did not always overlap across sites, indicating that bat activity within the farm was not limited to foraging. Lastly, I found a weak positive, but not statistically significant, relationship between insect abundance and bat activity. The findings of this study maintain that quantifying insect abundance remains a challenging task, especially in a wind farm environment, due to the large temporal and spatial variations in distribution of flying insects. Nonetheless, due to the considerable lack of empirical data on insect presence and community composition in Norwegian wind farms, it is crucial to continue to survey wind farms in order to better understand the effects that wind power development has on both bats and flying insects
