There have also been sightings of otter and water vole. Many species of wading birds and water vole inhabit the loch shore. The European Otter has been known to actively attack mink preying upon water vole. It also has one of the most dense water vole populations in the country. This is the highest reintroduction of water vole in the UK. They may attack if their territory is invaded by another water vole. The mammals seen around Duddingston Loch include otter, hedgehog and water vole. It has also been found that grazing affects the water vole populations as well. Mammals on the reserve include harvest mouse, water vole and European hare. The river and its tributaries support populations of European water vole ("Arvicola amphibius"). In large river floodlands, water vole are common prey. Additional wildlife species of note for this reserve include otter and water vole. The otter is seen here occasionally, as is the now 'uncommon' water vole. The water vole ("Microtus richardsoni") is the largest North American vole. The water vole is the second largest arvicoline in its range (after the muskrat).