Otter numbers rebound, but cities bring new dangers

Finland’s otter population has doubled, but the animals face growing risks as they move into urban environments, Yle reports. A wildlife rehabilitation centre in Orimattila is treating more otters each year.

There are currently six otter pups in the care of centre operator Sari Valtanen. The animals have arrived dehydrated and in very poor condition, often after being orphaned. Some have been so weak that their survival was uncertain.

Otter numbers doubled between 1989 and 2013, and the population is now estimated at up to 4,000. The species was classified as viable again in 2015. The estimate is based on snow-track counts and observations made during bird monitoring, rather than a precise population survey. The population has remained at roughly its current level in recent years.

Valtanen keeps the pups wary of people so they can return to the wild at 12 to 15 months old, around the age when their mothers would naturally wean them. All the otter pups she has cared for have been released back into the wild.

Urban areas can offer otters food and flowing water that stays open in winter, but they also bring hazards. Traffic, dogs, predators, fishing nets and fish traps can injure them. Bridges can trap otters, and other water construction also poses risks, says Katja Ikonen, a senior specialist at the Natural Resources Institute Finland.

Caring for otters requires large quantities of fish and enrichment that supports their return to the wild. The animals are strong and flexible, with sharp teeth, making them difficult to handle. The centre’s work is partly funded by the Capital Region Animal Welfare Association.