Institute of Avian Research
An der Vogelwarte 21
Tel.: +49 4421 9689 14
Email: sandra.bouwhuis@ ifv-vogelwarte.de
I am an evolutionary ecologist with a specific interest in the causes and consequences of within-individual change in life-history traits and between-individual variation in life-history strategies. I mostly conduct analyses on long- term individual-based data sets collected in wild populations, and have so far had the pleasure to work on great tits (Parus major), pre- industrial humans (Homo sapiens) and common terns (Sterna hirundo).
My current work focuses on the common tern. The common tern is a Nearctic and Palearctic colonially breeding and migratory seabird. The data we collect come from a long-term study population located in the Banter See at Wilhelmshaven on the German North Sea coast. In 1992, 101 adult birds were caught and marked with transponders, and since 1992 all locally hatched birds have similarly been marked with a transponder shortly prior to fledging. The colony site consists of 6 concrete islands, each of which measures 10 by 5 meter and is surrounded by a 60 cm wall. The walls support 44 platforms for terns to land on, and each platform is equipped with an antenna which reads transponder codes to record the presence of all transponder-marked individuals. During incubation, which is shared between partners, additional antennae are placed at each nest for 1–2 days to identify breeding individuals. Combined with 3-times-weekly checks of nests to record reproductive parameters and to mark offspring, these methods enable the systematic and remote documentation of individual presence and reproductive performance at the colony. Once birds have established themselves as Banter See breeders, their re-sighting probability is almost 100% and their return rate, not conditional of survival, is 90%, such that we can collect data over long individual life cycles. Since 1992, the number of breeding pairs has ranged between 90 and 650.
Making use of the long-term data set, I've recently found sex-specific pathways of parental age effects on offspring lifetime reproductive success: recruited sons from older fathers suffer from a reduced lifespan, while recruited daughters from older mothers suffer from reduced reproductive performance throughout life (Bouwhuis et al. 2015 Evolution). The latter effect may (partly) be explained by daughters from older mothers fledging with a reduced body mass and remaining a low body mass throughout life. With a team of Msc students I now investigate two potential underlying mechanisms and study sex-specific offspring food intake, growth and telomere length in relation to parental age and sex. In addition, and in collaboration with Dr. Miriam Liedvogel, I have been awarded a grant by the Max Planck Institute to start work on the epigenetics of the observed parental age effects. We’ll first sequence, assemble and annotate the common tern genome, then use repeated blood samples of parents, and their offspring produced at different ages, to characterise their DNA methylation status.
In addition, working with Dr. Oscar Vedder, I am aiming to investigate the extent to which offspring growth, telomere dynamics and development are determined pre-hatching and to which extent rearing conditions play a role, using both a correlative and an experimental approach. Moreover, we are aiming to extend our investigations of long-term fitness consequences of variation in the natal and early-life environment and to also explore the quantitative genetic basis of (age- and sex-specific patterns in) various traits.
In collaboration with Dr. Heiko Schmaljohann and Dr. Jacob González-Solís, we have recently started to extend our view of the common tern beyond the breeding season and will study migration of the Banter See breeders in relation to natal environmental variation and the phenotypic and genetic characteristics of the birds.
Working with Dr. Coraline Bichet, I will be extending the current projects by joining the Banter See common tern microsattelite project facilitated by professor Michael Wink (University of Heidelberg) as well as by collecting measures of immunocompetence, DNA damage and oxidative processes.
If you are interested in joining us in any of these projects, or have an interesting project to add, please get in touch. There are several grant opportunities that I would be happy to explore with you.