The wild horses of Dülmen live – largely uninfluenced by humans – relatively freely and all year round in the Merfelder Bruch.
Every year on the last Saturday in May since 1907, the young stallions are caught by hand and auctioned off at a much attended event. The stallions only live with the herd from May to September to control the birth dates of the foals. The herd itself is divided into family groups consisting of related mares and their foals, each of which is led by a lead mare.