Marcel E. Visser, Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
Spring temperatures are increasing due to climate change and in the Northern Hemispere this has had profound effects on the spring phenology of many organisms. These shifts in phenology however vary substantially among species, with predatory species shifting only at half the rate as their prey. This leads to so-called phenological mismatches: the phenology of predators and their prey get out of synchrony. I will give an overview of these mismatches, the evolutionary consequences and the population consequences using data from our long-term study (1955-present) on a small song bird, the great tit (Parus major). I will present data of birds, caterpillars and trees to show that to understand patterns of selection on the phenology of the birds we need to take the phenology of the entire food chain into account. Next, I will switch gears and focus on the potential for genetic change in response to selection on phenology in great tits. We have been studying the genetics and physiology underlying phenology by creating selection lines of early and late reproducing great tits, using genomic rather than phenotypic selection. We breed great tits of these selection lines under controlled conditions and look at their lay dates as well as at RNA expression. As a final step we introduced selection line eggs into our wild population and in 2018 we will have the first F4 offspring breeding in the wild and we can then measure their fitness depending on their phenology. Next, I will present data on how phenological mismatches have knock-on effect at the population level. In the last part of the talk, I will discuss these finding in the light of the theme of the meeting: One Planet, Two Hemispheres, Many Regions.