- Data from: Increasing frequency of low summer precipitation synchronizes dynamics and compromises metapopulation stability in the Glanville fritillary butterfly(2015-05-07) Tack, Ayco J. M.; Mononen, Tommi; Hanski, Ilkka; University of Helsinki - Tack, Ayco J. M.; Aalto University - Mononen, Tommi; University of Helsinki - Hanski, Ilkka