Adrian Davies / Cicada turret, or chimney, formed by underground larva. Sabah, Borneo.

Richard Du Toit / Baboon spoor. Moremi reserve, Botswana, Southern Africa

Bruno D'Amicis / Marsican / Apennine brown bear (Ursus arctos marsicanus) claw marks on Beech (Fagus sylvatica) tree bark in old growth beech forest. Abruzzo, Lazio and Molise National Park / Parco Nazionale d'Abr...

Colin Varndell / Hazel nut (Corylus avellana) cases on forest floor, broken by grey squirrel. Dorset, UK August.

Ashley Cooper / Polar Bear footprints in melting permafrost on Northern Svalbard. July 2013

Matthew Maran / Goat willow (Salix caprea) felled by a Eurasian beaver (Castor fiber) with teeth marks The riverside tree will resprout with new shoots supplying a source of food for the beavers for years to come. De...

Matthew Maran / Goat willow (Salix caprea) felled by a Eurasian beaver (Castor fiber). The riverside tree will resprout with new shoots supplying a source of food for the beavers for years to come. Devon, England, UK...

Igor Shpilenok / Siberian tiger (Panthera tigris tigris) scat, Sikhote-Alin Mountain Range, Sikhote-Alin Nature Reserve, Primorye Krai, Russian Far East. May.

Nick Upton / Hemlock water dropwort stem (Oenanthe crocata) cut by a Water vole (Arvicola amphibius) at a tell-tale 45 degree angle, found during a survey for signs of Water vole activity. This plant is highly to...

Nick Upton / Footprints of Water voles (Arvicola amphibius), or possibly Brown rats (Rattus norvegicus) pointed out on a muddy river bank, found during a survey for signs of Water voles, near Bude, Cornwall, UK, A...

Tui De Roy / Erect-crested penguins (Eudyptes sclateri) feathers left behind after seasonal moulting. Antipodes Island, New Zealand Sub-Antarctic Islands. Endemic to Antipodes and Bounty Islands. Endangered specie...

Tui De Roy / Erect-crested penguins (Eudyptes sclateri) feathers left behind after seasonal moulting. Antipodes Island, New Zealand Sub-Antarctic Islands. Endemic to Antipodes and Bounty Islands. Endangered specie...

Staffan Widstrand / Rhino rubbing rock, iMfolozi National Park, South Africa

Staffan Widstrand / Rhino rubbing post rhinos, both black and white rhinos. They scratch themselves on this tree, since decades back. iMfolozi National Park, South Africa

Adrian Davies / Common birch pygmy moth (Stigmella betulicola) larva mine in Silver Birch leaf. Surrey, England, UK.

Adrian Davies / Common birch pygmy moth (Stigmella betulicola) mine in Silver Birch leaf. Surrey, England, UK.

Adrian Davies / Scarlet caterpillar club (Cordyceps militaris) a parasitic fungus on the buried larvae of butterflies and moths. Sussex, England, UK, November.

Edwin Giesbers / European bison (Bison bonasus) damage on trees, causde by rubbing against the bark, Zuid-Kennemerland National Park, the Netherlands. January. Reintroduced species.

Roland Seitre / Spotted hyaena (Crocuta crocuta) footprints, Senegal.

Roland Seitre / Spotted hyaena (Crocuta crocuta) faeces, Senegal.

Nick Upton / Downy birch tree (Betula pubescens) heavily gnawed by Eurasian beavers (Castor fiber) and close to being felled, in large enclosure, Devon Beaver Project, Devon Wildlife Trust, Devon, UK, May.

Nick Upton / Rear, webbed footprint of Eurasian beaver (Castor fiber) in mud within enclosure, Devon Beaver Project, Devon Wildlife Trust, Devon, UK, May.

Nick Upton / Toothmarks left by Eurasian beaver (Castor fiber) that has stripped bark from a cut tree branch within a large woodland enclosure, Devon Beaver Project, Devon Wildlife Trust, Devon, UK, April 2015.

Nick Upton / Toothmarks left by Eurasian beaver (Castor fiber) that has stripped bark from a cut tree branch within a large woodland enclosure, Devon Beaver Project, Devon Wildlife Trust, Devon, UK, April 2015.

Nick Upton / Toothmarks of Eurasian beavers (Castor fiber) on Willow tree (Salix sp.) trunk within a large woodland enclosure, Devon Beaver Project, Devon Wildlife Trust, Devon, UK, April 2015.

Nick Upton / Tree felled by Eurasian beavers (Castor fiber) on the banks of the River Otter, Devon, UK, March.

Nick Upton / Willow tree (Salix sp.) heavily gnawed by Eurasian beavers (Castor fiber) within a large woodland enclosure, Devon Beaver Project, Devon Wildlife Trust, Devon, UK, April.

Nick Upton / Willow tree (Salix sp.) trunk heavily gnawed by Eurasian beavers (Castor fiber) within a large woodland enclosure, Devon Beaver Project, Devon Wildlife Trust, Devon, UK, April.

Nick Upton / Willow tree (Salix sp.) trunk heavily gnawed by Eurasian beavers (Castor fiber) within a large woodland enclosure, Devon Beaver Project, Devon Wildlife Trust, Devon, UK, April.

Nick Upton / Willow tree (Salix sp.) heavily gnawed by Eurasian beavers (Castor fiber) within a large woodland enclosure, Devon Beaver Project, Devon Wildlife Trust, Devon, UK, April.

Nick Upton / Willow tree (Salix sp.) heavily gnawed by Eurasian beavers (Castor fiber) within a large woodland enclosure, Devon Beaver Project, Devon Wildlife Trust, Devon, UK, April.

Nick Upton / Willow trees (Salix sp.) gnawed and felled by Eurasian beavers (Castor fiber), Wiltshire, UK, April.

Nick Upton / Young Willow tree (Salix sp.) felled by Eurasian beavers (Castor fiber), Gloucestershire, UK, April.

Nick Upton / Young Willow trees (Salix sp.) felled and gnawed by Eurasian beavers (Castor fiber), Gloucestershire, UK, April.

Nick Upton / Young Willow tree (Salix sp.) felled by Eurasian beavers (Castor fiber), Gloucestershire, UK, April.

Nick Upton / Young Willow tree (Salix sp.) felled by Eurasian beavers (Castor fiber), Gloucestershire, UK, April.

David Tipling / Brown hare (Lepus europaeus) tracks in the snow, Norfolk, UK, January.

Adrian Davies / Otter (Lutra lutra) dropping / spraint on rock at edge of lake. Devon, England, July.

Nick Upton / Close up of plant stem cut by Water vole (Arvicola amphibius) at 45 degree angle. Found on lake bank during survey for signs of Water vole activity, near Bude, Cornwall, UK, April 2014.

Nick Upton / Rebecca Northey of Derek Gow Consultancy inspecting stems of Stinging nettle (Urtica dioica) cut by Water vole (Arvicola amphibius) and left near its burrow entrance on river bank. Found during survey...

Nick Upton / Dani Siddall of Derek Gow Consultancy looking at stem of Hemlock water dropwort (Oenanthe crocata) cut by Water vole (Arvicola amphibius), and left on river bank. Found during survey for signs of Wate...

Ann & Steve Toon / Black-backed jackal (Canis mesomelas) footprints, Dead Vlei, Namib Desert, Namibia, April

Ann & Steve Toon / Black-backed jackal (Canis mesomelas) footprints, Dead Vlei, Namib Desert, Namibia, April

Ann & Steve Toon / Burrow of Dancing white lady spider (Leucorchestris arenicola), Namib Desert, Namibia, May.

Ann & Steve Toon / Burrow of Dancing white lady spider (Leucorchestris arenicola), Namib Desert, Namibia, May.

Suzi Eszterhas / Cheetah {Acinonyx jubatus} pawprint, Cheetah Conservation Fund, Namibia

Staffan Widstrand / Saami / Laplander guide shows ecotourists wolverine tracks in snow, Sweden.

Richard Du Toit / Male Leopard tracks and faeces {Panthera pardus}, early morning Malamala GR South Africa Winter

Tony Heald / African lion track in wet sand {Panthera leo} Kaokoland, Namibia

Richard Du Toit / Desert Lion footprints in sand {Panthera leo} Hoarusib river, Skeleton Coast NP, Namibia

Pete Oxford / Lion tracks in sand Clay castles, Skeleton coast, Namibia

Richard Du Toit / Hippo spoor. Moremi reserve, Botswana, Southern Africa

Richard Du Toit / Lion tracks (Panthera leo). Savuti-Chobe NP< Botswana, Southern Africa

Nick Garbutt / Downy birch (Betula pubescens) nearly felled by a Eurasian beaver (Castor fiber). Shores of Loch Aigas, Aigas Field Centre, near Inverness, Scotland, UK. October.

John Waters / Signs of European Beaver (Castor fiber) activity, chewed trunks of birch trees in boggy woodland. Home of a successful Beaver re-introduction project at Knapdale Forest, Argyll, Scotland, UK, Septembe...

John Waters / Signs of the presence of European beavers (Castor fiber) including chewed tree trunks in a boggy birch woodland. Site of successful re-introduction, Knapdale Forest, Argyll, Scotland, UK, September.