Abstract
This study examined the abiotic and biotic characteristics of ecosystems that allow expression of a life history called ferox trout, the colloquial name given to brown trout Salmo trutta adopting a piscivorous life history strategy, an apex predator in post‐glacial lakes in northern Europe. One hundred and ninety‐two lakes in Scotland show evidence of currently, or historically, supporting ferox S. trutta ; their presence was predicted in logistic models by larger and deeper lakes with a large catchment that also support populations of Arctic charr Salvelinus alpinus .