Individuals within a population may considerably differ in behavior from one another. Although
inheritable traits play an important role in generating and maintaining such intraspecific variation,
the latter may also be due to prior experience. In long-lived species, in particular, there is a large
potential for related individuals to diverge over time because of accumulated experiences. To what
extent genetic processes or prior experience drive intraspecific variation in behavior has important
consequences for population dynamics, mainly because variation driven by prior experience
changes over much shorter timescales compared to trans-generation changes generated by genetic
processes. Still, studies on intraspecific variation so far mainly focused on genetic processes in shortlived
species. In this project, I will study the ontogeny of individual specialization in a long-lived
coastal bird, the Lesser Black-backed Gull (Larus fuscus). Individuals show strong variation in
migration and feeding strategies within single colonies, which remains largely unexplained. To
bridge this knowledge gap, I will employ state-of-the-art GPS loggers to track 15 sibling pairs from
parents with known migration and feeding strategies. Based on a multi-year data set, I will assess to
what extent migration and feeding strategies are more similar between related individuals, and
whether differences can be related to stochastic experiences, such as extreme weather events
during migration.