Does the environment change the expression of trait syndromes? Plastic pace-of-life in a variable world

• Applicant: Dr. Alexandra Cones
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 537193560

Organisms express multiple traits, and often the expression of one trait is correlated with the expression of other traits. When traits correlate in consistent ways, they form a "syndrome". For example, species that are long-lived tend to produce few offspring and provide extended parental care (they express a "slow pace-of-life syndrome"), whereas species that are short-lived tend to produce many offspring with limited parental care (considered a "fast pace-of-life syndrome"). However, when you compare individual organisms within a species, evidence for these pace-of-life syndromes is mixed. One possible explanation is that the correlations between traits are not genetically fixed, but instead, change with the environment. For example, great tits that are "bolder" tend to breed later in the year, but when predation risk is high, this relationship flips and "shyer" individuals breed later than bolder individuals. Because the majority of variation in traits is, on average, due to environmental effects, I predict that environmental effects on the expression of trait syndromes may be common. However, little is known about this phenomenon because it requires large amounts of data and complex statistical tools to examine. I aim to take advantage of this opportunity by investigating environmental effects on trait syndromes in breeding birds. By collaborating with researchers in the "SPI-Birds Network", I will have access to large amounts of data on bird populations across Europe. First, I will use this data to determine whether pace-of-life syndromes are genetically fixed or phenotypically plastic to the environment. Second, I will conduct my own experiment by manipulating the competitive environment of sympatric populations of great tits and blue tits located in Germany. I will be able to combine my newly collected data with previously collected data from these populations to amass a sufficiently robust, seven-year experimental dataset. I will analyze these data using multivariate mixed-effect models, which I have used throughout my graduate research. Further, I will test the accuracy and precision of my results by simulating my data using the newly developed "squidSim" package in R. Because I will be using large datasets, combining observational and experimental approaches, and comparing patterns in different species, my results will reveal the extent to which the environment causes changes in the expression of trait syndromes, and whether these effects are generalizable across species or differ based on specific species ecology. Overall, if my proposed project is funded, I believe that I will be able to increase our understanding of the evolution of complex phenotypes in variable environments, and I hope to provide an analytical template for future investigations of these effects.

• DFG Programme: Research Grants