You might not expect to see otters in the Arboretum, but not so long ago they were an important part of southern Minnesota river ecosystems—including our own Cannon river. Throughout the state, populations of the North American river otter declined in the 19^th century as they were hunted for their fur and their wetland habitats were drained and destroyed. There are still significant otter populations in Northern Minnesota, but they have been absent from this region over a century.

Fortunately, otters have been making a comeback in recent years. Otter populations have re-established throughout the state due to the restoration of their wetland habitats and other conservation efforts. The return of otters to Minnesota’s rivers and lakes comes with ecological benefits. They are considered an indicator species for healthy ecosystems because they require habitats with clean water and plentiful resources. For this reason, the presence of otters bodes well for aquatic habitats in general. As the state’s largest aquatic carnivore, they also fill an important ecological niche in freshwater ecosystems.

In the past few years, otter tracks have been spotted in Heath Creek—a tributary that flows into the Cannon river in Northfield—and in the Cannon River Wilderness Area near Faribault. Arboretum staff have even seen evidence of otters in the Arboretum this winter: tracks in the snow where they have slid down the river bank into the Cannon. These signs indicate that, as their populations expand further south down the Mississippi river valley, more otters will come to our own Arboretum!