Visit my new personal website!
Since March 2007 I am employed as a Ph.D. student at the Resource Ecology Group. My research focuses on the flexibility of migration strategies and its consequences for parental care behaviour. Parental care strategies are optimized with respect to current reproductive success and expected future reproductive success. Species that have little to expect from the future will thus focus their parental investment on their current offspring, whereas species with more ‘future’ will save some investment for future generations of offspring, as a too large investment may increase risk of predation or starvation and thus the loss of much expected future reproductive success.
My study focuses on the Barnacle goose, which has both a migratory and non-migratory population within the same flyway. I am interested in what this different lifestyle means for the parental care behaviour of both populations and what the potential consequences are. Additionally, I am interested in the recent delay of spring migration of the (still migratory) Barnacle geese. What are the causes, and what are the behavioural consequences?
My work consists of theoretical modeling, fieldwork and genetics. Hopefully the integration of these disciplines will provide answers to my questions, and can these in turn provide some understanding of the differences between non-migratory and migratory behaviour within this species.
Social behaviour
What influences the duration of parental care? Why do individuals cooperate when foraging? How does a changed environment affect these decisions? Geese are a very good study system for these questions, because of the gregarious behaviour, changes in migration behaviour and their high numbers (never a lack of data).
Cultural evolution
Cultural evolution focus on traits that are not transmitted between individuals via genes, but via some form of learning. The interesting thing here is that it allows individuals to adapt much faster to new conditions than when the behaviour would be hard wired in their genes. A possible disadvantage of cultural transmission is that the it causes conservatism, i.e., that the individual is behaving in a certain way because all the others do so, not and because it is the optimal behaviour. In geese, the migration strategy is culturally transmitted. Offspring learn or copy the migration strategy from parents, which is possible because of the long parent-offspring association. In the case of Barnacle geese, migration changed, implying that somehow the transmission between experienced and naïve individuals went ‘wrong’. I use all the above logic to explain the role of culture in the evolution of new migration strategies in Barnacle geese.
Population genetics
Together with colleagues from (among others) the Animal Breeding and Genetics Group, Netherlands Institute of Ecology and Groningen University we are currently developing a SNP marker set to study the population structure of the Barnacle goose populations in Europe.
Publications
R.M. Jonker, M.W. Kuiper, L. Snijders, S.E. Van Wieren, R.C. Ydenberg, H.H.T. Prins. 2011. Divergence in timing of parental care and migration in Barnacle geese. Behavioral Ecology 22(2): 326-331
R.M. Jonker, G. Eichhorn, F. Van Langevelde, S. Bauer. 2010. Predation danger can explain changes in timing of migration: the case of the Barnacle goose. PLoS One 5(6) : e11369.
R.H.J.M. Kurvers, K. Van Oers, B. Nolet, R.M. Jonker, S. E. van Wieren, H.H.T. Prins and R.C. Ydenberg. 2010. Personality Predicts the Use of Social Information. Ecology Letters 13:829-837
Oral communications
R.M. Jonker, S.E. Van Wieren, R.C. Ydenberg, H.H.T. Prins. 2010. Migration, who cares? Netherlands Annual Ecology Meeting, Lunteren, The Netherlands.
R.M. Jonker, S.E. Van Wieren, R.C. Ydenberg, H.H.T. Prins 2009. Changes in migratory behavior cause changes in parental care behavior of Barnacle geese. Les Ecologiste Seminar series, Simon Fraser University, Vancouver, Canada.
R.M. Jonker, S.E. Van Wieren, R.C. Ydenberg, H.H.T. Prins. 2008. How to lose a kid in 10 months? 14th European Meeting for PhD Students in Evolutionary Biology, Einsiedeln, Switzerland.
Poster presentations
R. M. Jonker, F. Huettmann, W.F. De Boer. Quantifying influences of disturbances on foraging behaviour and movement pattern of Caribou (Rangifer tarandus granti). 7th Student Conference on Conservation Science, University of Cambridge. Cambridge, United Kingdom 2006
R. M. Jonker, S.E. Van Wieren, R.C. Ydenberg, H.H.T. Prins. Extended parental care and migration strategies. Netherlands Annual Ecology Meeting, Lunteren, The Netherlands 2008
Media coverage
Zeearend houdt brandgans hier - Bionieuws 4 september 2010
Ganzen bestuderen met virtuele Tomtom (newspaper Trouw 24-8-2010, in Dutch)
Conference /seminar organization
Wageningen Evolution and Ecology Seminars (WEES)
Member of organization committee.
http://www.gen.wur.nl/UK/WEES/
15th Annual European Meeting of PhD Students in Evolutionary Biology (EMPSEB)
Member of organization committee.
http://www.empseb2009.nl/drupal/
