Genetic assessment of the subspecies status of Eurasian Magpies (Pica pica) in Norway

Abstract

Based on phenotypes, two subspecies of Eurasian Magpies (Pica pica) are recognized in Norway, with nominate P. p. pica in southern Norway, and P. p. fennorum in northern Norway. In this study, we investigated whether there are genetically distinct groups of Magpies in Norway, which can be considered in the discussion of the subspecies status. We collected DNA from 61 Magpies from seven locations in Norway, and measured genetic diversity using two types of markers: mitochondrial DNA sequences and microsatellites. Genetic differentiation among the Magpies was extremely low. Most of the variance was within populations, and the population identity and the putative subspecies border did not explain the genetic variance among the samples. Although microsatellite markers indicated genetic differentiation, the pattern was not consistent with the geographic locations of the sampling sites. Mismatch analysis suggested that the Magpie populations in Norway were formed by rapid expansion. Our results suggest that all the Magpies in Norway have originated from the same refugia after the last glaciation, their colonization in Norway happened quickly, and that the subspecies status of Magpies in Norway needs to be reconsidered.