Five Films / Female Grey seal (Halichoerus grypus) defending pup on beach, chasing male away, Horsey, Norfolk, November.

Robert Thompson / Sawfly larvae (Nematus pavidus) defensive posture, Peatlands Park, County Armagh, Northern Ireland. September.

Jordi Chias / European barracuda (Sphyraena sphyraena) and Bluefish (Pomatomus saltatrix) circling baitball of Atlantic horse mackerel (Trachurus trachurus) Formigas Islets, Azores. Finalist in the Underwater Categ...

Paul Bertner / Spiny Spider (Gasteracantha falcicornis), Udzungwa Mountains National Park, Tanzania

Alan Murphy/ BIA / Killdeer (Charadrius vociferus) in broken wing display, Texas

Michael Milicia/ BIA / Piping Plover (Charadrius melodus) in broken wing display, Massachusetts

Hiroya Minakuchi / Jellyfish (Spirocodon saltator), Japan

Chien Lee / Red Stink Bug (Pycanum rubeus) hatchlings cluster to amplify the effect of their aposematic warning coloration, Malaysia

Doug Perrine / Female Hawaiian monk seal (Monachus schauinslandi) defending her pup from two males, which are aggressive with each other, Molokai Island, Hawaii, USA.

Michael Pitts / Gentoo penguins (Pygoscelis papua) calling and defending their eggs from Southern Skua (Stercorarius antarcticus) hunting for unattended eggs or chicks, Sea Lion island, The Falklands, South Atlantic.

Sergey Gorshkov / Arctic Fox (Alopex lagopus) chasing Snow Goose (Chen caerulesens) off its nest, Wrangel Island, Russia

Sergey Gorshkov / Snowy Owl (Nyctea scandiaca) chick in defensive posture, Wrangel Island, Russia