Gary Bell/ Oceanwide / Strawberry Land Hermit Crab (Coenobita perlatus) tracks on beach, Keeling Islands, Australia

Richard Du Toit / Sociable Weaver (Philetairus socius) nest, Kgalagadi Transfrontier Park, South Africa

Mark Raycroft / Elk (Cervus elaphus) large bull and harem of cows crossing railroad tracks in the mountains

Konrad Wothe / Firefly (Lamprohiza splendidula) light tracks in forest, Bavaria, Germany

Christian Ziegler / Southern Cassowary (Casuarius casuarius) footprint, Queensland, Australia

Christian Ziegler / Blue Quondong (Elaeocarpus angustifolius) seeds germinating from Southern Cassowary (Casuarius casuarius) droppings, Daintree National Park, Queensland, Australia

David Pike / Magpie (Pica pica) perched on a public footpath sign, Essex, UK, April.