Bayesian state-space modelling of metapopulation dynamics in the Glanville fritillary butterfly
Speaker: Dr. Phil Harrison (CREEM)
I had meant to give this talk over a year ago when I returned to CREEM, so hopefully better late than never I’ll give it now! During the talk I’ll go into some depth on the main modelling work I did during my time in Ilkka Hanski’s Metapopulation Research Group (MRG) in Finland. Owing to the fact that the
Glanville fritillary has been extensively studied since 1993 there exists a large amount of data and a detailed understanding of its life history. Consequently we were able to formulate a very detailed individual-based model (IBM) to describe this system. During the talk I’ll describe the trials I went
through getting the IBM to fit the data and the strategy that worked in the end including merging some ideas from particle filtering into the MCMC updating. We also derived from the IBM a population-based stochastic patch occupancy model (SPOM). The IBM was fit to bi-annual counts of larval groups, whereas the SPOM was fit to a simplified version of the data (the annual presence or absence of local populations). I’ll show comparisons of the parameter estimates, model fits, and predictive abilities of two models of metapopulation dynamics (the IBM and SPOM). Finally I’ll discuss the biological insights we were able to gain from this modelling exercise. The work was published in Ecological Monographs in 2011 with the same title as I have for the talk (but with the American spelling for modelling).