Bence Mate / Caspian gulls (Larus cachinnans) juveniles fighting, Lake Csaj, Kiskunsagi National Park, Pusztaszer, Hungary. March.

David Kjaer / Yellow-legged Gull (Larus cachinnans) & two Juvenile Herring Gull (Larus argentatus) catching fish and fighting, Poland

Hanne & Jens Eriksen / Caspian tern (Hydroprogne caspia) with open beak, in shallow water. Oman, March.

John Chan / Caspian tern (Hydroprogne caspia) plunge diving near a group of Elegant terns (Thalasseus elegans) gathering at breeding grounds, Southern California, USA, March.

Loic Poidevin / Caspian gull (Larus cachinnans) perched on tree stump eating fish caught by Sea eagle. Black Sea, Danube Delta, Romania. May.

Sylvain Cordier / Caspian gull (Larus cachinnans) in flight, Socotra Island UNESCO World Heritage Site, Yemen.

Jussi Murtosaari / Caspian tern (Hydroprogne caspia) with fish prey, Finland, April.

Andy Trowbridge / Caspian Tern (Sterna caspia) in flight. Lake Forsyth, Banks Peninsula, Canterbury, New Zealand. August.

Andy Trowbridge / Caspian Tern (Sterna caspia) in flight. Ashley River, Canterbury, New Zealand. August.

Martin Gabriel / Hundreds of Heuglin's gulls (Larus heuglini) and Caspian gulls (Larus cachinnans) sourround fishermen as they land their catch, Salalah, Sultanate of Oman, February.

Hanne & Jens Eriksen / Caspian tern (Hydroprogne caspia) in flight looking for food, Oman, August

Hanne & Jens Eriksen / Caspian tern (Hydroprogne caspia) in flight with fish, Oman, November