Eurasian otters maintain large waterway territories that provide the prey resources needed for their high metabolic demands. Understanding territorial dynamics informs effective otter conservation.
Otter welfare within territorial systems involves regular low-level stress from boundary maintenance and occasional acute welfare harm from territorial fights. Dispersing juveniles face the greatest welfare challenge: finding unoccupied territory in waterways where suitable habitat is already held by established adults. Juveniles that cannot establish territories starve. The welfare of individual otters is directly linked to prey fish abundance in their territory - degraded rivers with low fish stocks cannot support the territory density needed to sustain growing otter populations.