- Data from: Long-term demographic surveys reveal a consistent relationship between average occupancy and abundance within local populations of a butterfly metapopulation(2019-11-11) Schulz, Torsti; Vanhatalo, Jarno; Saastamoinen, Marjo; University of Helsinki - Schulz, Torsti; University of Helsinki - Vanhatalo, Jarno; University of Helsinki - Saastamoinen, Marjo