We built an otter holt on the Great Ouse river.
The otter feeds mainly on fish, amphibians and crustaceans. Otters have their cubs in underground burrows, known as 'holts'. Otters are well suited to a life on the water as they have webbed feet, dense fur to keep them warm, and can close their ears and nose when underwater. They require clean rivers, with an abundant source of food and plenty of vegetation to hide their secluded holts.