Phenology is the annual timing of biological spring events, and includes the timing of tree budburst, the appearance of insects, and the timing of egg laying in birds. Climate warming causes phenologies of many organisms to advance, but not every level of the food web responds at the same rate to temperature. For example, the timing of the caterpillar peak in broad leaved forests generally advances more than the timing of birds that depend on the caterpillars. This is referred to as trophic or phenological mismatch. Mismatch may cause a lower reproductive success in birds, because the birds may lack the food the need to raise their young. Many previous studies have looked at the effect of the timing of caterpillars on the breeding success of species that eat caterpillars (especially in resident tits and migratory flycatchers), but few have considered whether tits and flycatchers may respond differently to temperature, and how this may affect the interactions between them. In this thesis, I show that tits and flycatchers do not respond at the same rates to temperature, and that this affects competition between them. For example, more synchrony between tits and flycatchers was associated with higher competition for nest boxes, resulting in tits killing more flycatchers. Furthermore, I showed that flycatcher use the timing of tits as a social cue to adjust their settlement decisions. Taken together, these results suggest that climate change may alter competitive interactions between species that use similar resources (caterpillars, nesting cavities).
|Qualification||Doctor of Philosophy|
|Place of Publication||[Groningen]|
|Publication status||Published - 2018|