The effective size of the Scandinavian wolf population is too small for both short- and long-term conservation.

The Scandinavian wolf population (Norway and Sweden) is intensively managed at a population size considered sustainable by managing authorities. As these authorities have decided to reduce the population to only 170 individuals, it is timely to evaluate this population size goal and to scrutinize underlying assumptions of recent simulation studies that inform population management. The effective size of a population determines the pace at which genetic diversity declines and inbreeding increases and plays a crucial role in short- and long-term extinction risks. Here, we use the complete published pedigree of the Scandinavian wolf population to precisely calculate the effective size Ne since the founding of the population, per year. Our results indicate the Ne is unsustainably low. Moreover, we find that recent simulation studies commissioned by the managing authorities greatly overestimate the effective size of the Scandinavian wolf population, questioning their usefulness to inform population management.