Practical considerations for evaluating effects of connectivity and harvest on transboundary carnivore populations

Abstract

Carnivore ecologists globally have eagerly embraced the remarkable advances in field techniques (eg GPS telemetry, genetic sampling) for studying movements and vital rates of wide-ranging species. However, equally impressive modelling tools also exist – but are less often used -- to illuminate practical management recommendations by marrying genetic and demographic outcomes of connectivity and harvest. I will focus on two related areas that demonstrate practical outcomes at the genetic – demographic interface, using examples from carnivores in North America and Scandinavia. First, genetic rules of thumb such as “One Migrant Per Generation” (OMPG) are best interpreted in a demographic context. Of course, this means that an immigrant serves as a ‘genetic migrant’ only if it breeds. However, a less recognized corollary is that the demographic costs and benefits of a given level of gene flow (e.g. OMPG) depend on life history traits such as population growth rate. Second, I will assert that among population connectivity can affect population growth rate more than within-population vital rates. This somewhat non-intuitive principle has substantial implications for managing wide-ranging species because it means that conventional management to improve population trends within a country may be less important to population persistence than management on or across administrative or national borders. Just as sophisticated cutting-edge tools have emerged to estimate movements and vital rates, tools also exist to integrate genetic and demographic processes in powerful new ways.