Cormorant fishing is a traditional fishing technique in which fishermen use trained cormorants to catch fish in rivers. To control the birds, the fishermen tie a loose snare near the base of the bird’s throat. The snare does not stop the bird from swallowing small fish, but prevents the bird from swallowing larger fish, which are held temporarily in their gullet. When a cormorant has caught a fish in its throat, the fisherman brings the bird back to the boat and has it regurgitate the fish.