Abundance of owls and bramblings Fringilla montifringilla in relation to mast seeding in south-eastern Sweden.
We investigated the relationship between mast seeding in beech Fagus sylvaticus and oak Quercus spp., and the occurrence of the rodent-dependent predators Tengmalm's Owl Aegolius funereus, Long-eared Owl Asio otus and Tawny Owl Strix alaco in south-eastern Sweden (Blekinge) 1992-2000. We also compared available data on seed production with data on winter flocks of Brambling Fringilla montifringill