Fabio Pupin / Red swamp crayfish (Procambarus clarcki), invasive species, captive, Italy, July.

MYN / Paul Marcellini / Sequence of an American alligator (Alligator mississippiensis) hatching from its egg, Palmdale, Florida, USA. Digital composite.

Ingo Arndt / American alligator (Alligator mississippiensis) split level, Everglades, USA, January.

Ingo Arndt / American Alligator (Alligator mississippiensis) split level, Everglades, USA, January.

Ingo Arndt / American Alligator (Alligator mississippiensis) in water, Everglades National Park, Florida

Staffan Widstrand / Wild Wonders of China / Crested myna starlings (Arcidotheres cristatellus) sitting on domestic waterbuffaloes (Bubalus domesticus), Poyang Ho Lake, Jiangxi province, China

Scott Leslie / American Alligator (Alligator mississippiensis) juvenile, Florida

George Sanker / Alligator (Alligator mississippienis) at the surface, with clouds reflected on the water, Everglades, Florida, USA, March.

Tim Fitzharris / American Alligator (Alligator mississippiensis), Everglades, Florida

Claudio Contreras / Tricoloured heron (Egretta tricolor), Guerrero Negro, Vizcaino Biosphere Reserve, Baja California Peninsula, Mexico, May

Jabruson / Common House Martin (Delichon urbicum) flying above pile of hardwood timber logs in storage depot. Lope National Park, Libreville, Gabon.

John Abbott / Yellow / Pale pitcher plant / trumpet (Sarracenia alata) growing in bog, Louisiana, USA, April