Cyril Ruoso / Ring-tailed Lemur (Lemur catta), Anja Park, Madagascar

Donald M. Jones / Black-tailed Prairie Dog (Cynomys ludovicianus) group, South Dakota

Donald M. Jones / Black-tailed Prairie Dog (Cynomys ludovicianus) pair greeting, South Dakota

Donald M. Jones / Black-tailed Prairie Dog (Cynomys ludovicianus) pair greeting, South Dakota

Juergen & Christine Sohns / Swamp Wallaby (Wallabia bicolor) mother and joey, Mount Lofty, South Australia, Australia

Yva Momatiuk & John Eastcott / Black-tailed Prairie Dog (Cynomys ludovicianus) on alert, Theodore Roosevelt National Park, North Dakota

Donald M. Jones / Black-tailed Gnatcatcher (Polioptila melanura), southwestern Arizona

Philippe Clement / Pair of Black-tailed godwits (Limosa limosa) courting and mating in wetland, Belgium, April

Nick Upton / Panning shot of a flock of Lapwings (Vanellus vanellus) landing on partially flooded pastureland near resting Black-tailed godwits (Limosa limosa) and grazing Wigeon (Anas penelope), Gloucestershire,...

Thomas Marent / Black-tailed Trogon (Trogon melanurus) male, Magdalena Valley, Colombia

Richard Du Toit / Black wildebeest (Connochaetus gnou) bull silhouetted at dawn, Rietvlei Nature Reserve, Gauteng Province, South Africa.

Richard Du Toit / Longtailed widowbird (Eupletes progne) male perched in flowers, Rietvlei Nature Reserve, South Africa.