Background & Aims

The marsh fritillary was studied not just because of its beauty, but because it is a vulnerable butterfly in Sweden, that suffered an intense decline in entire Europe in the past century. It is a habitat specialist and it is important to study the species to halt a future decline. I mentioned before something about metapopulation, but what is that? A metapopulation is when the population of a species is distributed in patches surrounded by a landscape matrix of unsuitable habitats for the species. Those patches are occasionally visited by individuals from the other local populations, and this migration mechanism is important to save patches of suffering local extinction.

So, now that we know what a metapopulation is, it is important to understand that for each species there are aspects of the environment that makes a patch more prone for a species to occupy, migrate or go locally extinct. Those aspects can be, for example, patch size or connectivity, and in my thesis I studied which of those aspects, also called habitat preferences, are important for occupancy, extinction, and colonization dynamics of the marsh fritillary butterfly. I also checked the habitat preferences for the larvae of the butterfly, on two scales, a larger scale where I analyzed the presence of larvae with one-hectare patch variables, and on a smaller scale, where I did the same but with variables that are in a 0.5 m2 plot scale. In addition, Gotland suffered from an intense drought in 2018, so I estimated the population size to keep track of the numbers and see if the species is doing a good recovery.