Maternal investment in offspring immunity via egg quality may be an adaptive evolutionary strategy shaped by natural selection. We investigated how maternal investment in eggs can influence offspring immunity by conducting two experiments. First, we manipulated foraging performance of the mothers before egg laying by attaching a small weight to their back feathers. During the nestling period, w...

Metals have been used by humans for thousands of years, and this has resulted in increased concentrations in the biosphere. The environment around pointsources, such as mines and smelters, are of particular concern, as metals may accumulate to high concentrations, and potentially reach levels toxic to the local flora and fauna. This thesis focuses on the effects on pied flycatcher populations o...

Assortative mating depends on species distinctiveness in traits and preferences, which can be challenging to maintain when and/or preferences are learned. This is because learning may cause individuals copy heterospecific signals. Juvenile songbirds possess innate sensory biases favouring them learn prefer conspecific songs, but the effectiveness of these relies consistent sufficient difference...

Understanding the ecology and conservation of bird species often requires accurate sex determination individuals. Species with sexually dimorphic plumage can usually be sexed in hand based on consistent definitive differences between sexes, but there are challenges related to (1) how sexual dimorphism develops age, (2) individuals that show intermediate visible morphological traits, or (3) subt...