Katholm at the island of Als

The small island previously belonged to a local farm in Dyndved and was a breeding ground for a very large seagull colony. The eggs were collected, and on the best days, up to 5,000 eggs could be collected per day. One of the last owners in the 1960s who collected and sold eggs was Nicolai Jespersen, and the seagull population was known at the time as Kloj's chickens.

Gulls still breed on the island today, but instead of a large population of black-headed gulls, it is now herring gulls and common gulls that dominate the scene. In addition, a pair of mute swans with a nest and the large seabird, the great black-backed gull, can also be seen.

Katholm is now a breeding ground for one of South Jutland's largest populations of eider ducks, and as this duck protects its eggs from gulls and crows by covering them with down, it needs to be able to leave the nest in peace.

The island is located within the 300-metre coastal zone, where sailing at speeds of over 5 knots is not permitted, and this also applies to the island's own coastline.

Katholm has been sold and is still privately owned, and to protect bird life, access is not permitted.