Gerrit Vyn / Willow Ptarmigan (Lagopus lagopus) male standing on snow covered ground, vocalising in spring courtship. Males retain the white body plumage of winter plumage and molt the head and neck feathers to th...

Rolf Nussbaumer / Chestnut-Breasted Coronet hummingbird (Boissonneaua matthewsii) adult feeding from fuchsia flower, Papallacta, Ecuador, Andes, South America, January

Lucas Bustamante / Russet-backed oropendola (Psarocolius angustifrons) building a nest. Tambopata National Reserve, Madre de Dios, Peru.

Nick Garbutt / Russet-backed oropendola (Psarocolius angustifrons), pair constructing nest. Manu Biosphere Reserve, Peru.

Magnus Lundgren / Wild Wonders of China / Fulvous forest skimmer, or Russet percher dragonfly (Neurothemis fulvia) female, Sai Kung, Hong Kong, China.

Alan Williams / Apple (Malus domestica) blossom variety 'Egremont Russet' in orchard, Cheshire, UK, May

Alan Williams / Apple (Malus domestica) blossom variety 'Egremont Russet' in orchard, Cheshire, UK, May

Konrad Wothe / Russet-backed oropendola (Psarocolius angustifrons) building a nest, Panguana Reserve, Huanuca Region, Peru.

Konrad Wothe / Russet-backed oropendola (Psarocolius angustifrons) bowing display, Panguana Reserve, Huanuca Region, Peru.

Konrad Wothe / Russet-backed oropendola (Psarocolius angustifrons) building a nest, Panguana Reserve, Huanuca Region, Peru.

Konrad Wothe / Russet-backed oropendola (Psarocolius angustifrons) building a nest, Panguana Reserve, Huanuca Region, Peru.

Konrad Wothe / Russet-backed oropendola (Psarocolius angustifrons) building a nest, Panguana Reserve, Huanuca Region, Peru.

Konrad Wothe / Russet-backed oropendola (Psarocolius angustifrons) building a nest, Panguana Reserve, Huanuca Region, Peru.

Konrad Wothe / Russet-backed oropendola (Psarocolius angustifrons) bowing display, Panguana Reserve, Huanuca Region, Peru.

Konrad Wothe / Russet-backed oropendola (Psarocolius angustifrons) bowing display, Panguana Reserve, Huanuca Region, Peru.

Konrad Wothe / Russet-backed oropendola (Psarocolius angustifrons) building a nest, Panguana Reserve, Huanuca Region, Peru.

Thomas Marent / Russet-backed Oropendola (Psarocolius angustifrons), Guacharo Cave National Park, Colombia

Roland Seitre / Moustached monkey (Cercopithecus erythrotis) portrait whilst feeding, captive, occurs in Cameroon, Equatorial Guinea, and Nigeria.

Konrad Wothe / Russet-backed Oropendola (Psarocolius angustifrons) nests in blooming Coral Tree (Erythrina sp) in lowland rainforest, Panguana Nature Reserve, Peru

Paul Hobson / Russet toughshank (Collybia dryophila), Nottinghamshire, UK, November.

Tui De Roy / Russet-crowned Warbler (Basileuterus coronatus), Andes, Ecuador

Dong Lei / Russet sparrow (Passer rutilans) perched, Lantsang Mekong river, Kawakarpo Mountain, Meri Snow Mountain National Park, Yunnan Province, China.

Dong Lei / Russet sparrow (Passer rutilans) perched, Lantsang Mekong river, Kawakarpo Mountain, Meri Snow Mountain National Park, Yunnan Province, China.

Dong Lei / Russet sparrow (Passer rutilans) feeding on insect, Lantsang Mekong river, Kawakarpo Mountain, Meri Snow Mountain National Park, Yunnan Province, China.

Tim Laman / Female Russet-backed Oropendula (Psarocolius angustifrons) building a nest at Napo Wildlife Center, Yasuni National Park, Orellana Province, Ecuador, July.

Tim Laman / Female Russet-backed Oropendula (Psarocolius angustifrons) at Napo Wildlife Center, Yasuni National Park, Orellana Province, Ecuador, July.

Tim Laman / Female Russet-backed Oropendula (Psarocolius angustifrons) at Napo Wildlife Center, Yasuni National Park, Orellana Province, Ecuador, July.

Bernard Castelein / Brown Mouse Lemur (Microcebus rufus) Ialasatra, Madagascar

Bernard Castelein / Brown Mouse Lemur (Microcebus rufus) Ialasatra, Madagascar

Bernard Castelein / Brown Mouse Lemur (Microcebus rufus) Ialasatra, Madagascar

Tui De Roy / Russet crowned warbler (Basileuterus coronatus) Bellavista cloud forest private reserve, 1700m altitude, Tandayapa Valley, Andean cloud forest, Ecuador

Bryan and Cherry Alexander / Reindeer lichen (Cladonia sp.) and the autumn russet catkins of Dwarf birch (Betula nana) on the tundra in Hurry Inlet. Scoresbysund, East Greenland, September.

David Welling / Russet-tipped Clubtail Dragonfly (Stylurus plagiatus) perching on foliage. Rio Grande Calley, Hidalgo County, Texas, USA.

Tui De Roy / Russet-crowned Warbler (Basileuterus coronatus), Bellavista Cloud Forest Reserve, Tandayapa Valley, Ecuador

Pete Oxford / Russet-crowned Warbler (Basileuterus coronatus) perched on lichen covered branch, captive, Podocarpus National Park, Ecuador

Gerrit Vyn / Willow Ptarmigan (Lagopus lagopus) male standing on snow covered ground, vocalising in spring courtship. Males retain the white body plumage of winter plumage and molt the head and neck feathers to th...

Gerrit Vyn / Willow Ptarmigan (Lagopus lagopus) male standing on snow covered ground, in spring. Males retain the white body plumage of winter plumage and molt the head and neck feathers to the russet brown summer...

Pete Oxford / Russet-crowned Warbler (Basileuterus coronatus), Podocarpus National Park, Ecuador

Andy Sands / Ruby Tiger moth (Phragmatobia fuliginosa) Hertforshire, England, UK

Andy Sands / Ruby Tiger moth (Phragmatobia fuliginosa) showing underwing, Hertforshire, England, UK

Rolf Nussbaumer / Dark-backed Wood-quail (Odontophorus melanonotus) adult, Mindo, Ecuador, Andes, South America, January

Rolf Nussbaumer / Giant Antpitta (Grallaria gigantea) adult, Paz de las aves, Mindo, Ecuador, Andes, South America, January

Rolf Nussbaumer / Chestnut-Breasted Coronet hummingbird (Boissonneaua matthewsii), adult perched, Papallacta, Ecuador, Andes, South America, January

Thomas Marent / Russet-backed Oropendola (Psarocolius angustifrons) on nest, Manu, Peru

Hermann Brehm / Russet backed oropendola (Psarocolius angustifrons) perched on branch, South America

Pete Oxford / Russet mouse lemur {Microcebus rufus} Kirindy, Madagascar

Pete Oxford / Russet mouse lemur {Microcebus rufus} held in hand to show small size, Kirindy, madagascar

Pete Oxford / Russet mouse lemur {Microcebus rufus} Montagne D'ambre NP, Madagascar

Pete Oxford / Russet mouse lemur held in hand {Microcebus rufus} captive, Kirindy Dry Forest Reserve, Madagascar

Luiz Claudio Marigo / Russet-mantled foliage gleaner (ovenbird) at nest in termite mound, Brazil. Endangered.

Luiz Claudio Marigo / Russet-mantled foliage gleaner (ovenbird) at nest in termite mound, Brazil. Endangered.

Michael & Patricia Fogden / Banded Kukri (Oligodon arnensis), India

Nigel Cattlin / Leaf and flower bud an apple twig swelling and starting to open in early spring Berkshire, England, UK.

Nigel Cattlin / Leaf and flower bud an apple twig swelling and starting to open in early spring Berkshire, England, UK.

Nigel Cattlin / Leaf and flower bud an apple twig swelling and starting to open in early spring Berkshire, England, UK.

Nigel Cattlin / Leaf and flower bud an apple twig swelling and starting to open in early spring Berkshire, England, UK.

Nigel Cattlin / Tight leaf and flower bud of an Apple twig in late winter beginning to swell and starting to open Berkshire, England, UK.

Nigel Cattlin / Tight leaf and flower bud of an Apple twig in late winter beginning to swell and starting to open Berkshire, England, UK.

Mathias Putze/ BIA / Russet Sparrow (Passer rutilans) male calling, Thimphu, Bhutan

Thomas Marent / Russet-backed Oropendola (Psarocolius angustifrons), Las Tangaras Bird Reserve, Colombia

Thomas Marent / Russet-backed Oropendola (Psarocolius angustifrons) displaying, Guacharo Cave National Park, Colombia

Pete Oxford / Russet backed oropola {Psarocolius augustifrons} Amazonia Peru

Tim Laman / Russet-backed oropendula (Psarocolius angustifrons) female, perched in tree with nesting material in beak, Napo Wildlife Center, Yasuni National Park, Orellana Province, Ecuador.

Tim Laman / Russet-backed oropendola (Psarocolius angustifrons) female, nest building, Napo Wildlife Center, Yasuni National Park, Orellana Province, Ecuador.

Nigel Cattlin / Egremont Russet apple tree (Malus domestica) blossom with young leaves in spring, Berkshire, UK. May.

Nigel Cattlin / Egremont Russet apple tree (Malus domestica) blossom with young leaves in spring, Berkshire, UK. May.

Tim Laman / Red-eared guenon (Cercopithecus erythrotis erythrotis) male, looking down from branch in rainforest, Bioko Island, Equatorial Guinea. Endangered.

Tim Laman / Red-eared guenon (Cercopithecus erythrotis erythrotis) male, looking down from branch in rainforest, Bioko Island, Equatorial Guinea. Endangered.

Joel Sartore / Photo Ark / Brown mouse lemur (Microcebus rufus) resting, portrait, Parc Botanique et Zoologique de Tsimbazaza, Madagascar. Captive.

Joel Sartore / Photo Ark / Brown mouse lemur (Microcebus rufus) portrait, Parc Botanique et Zoologique de Tsimbazaza, Madagascar. Captive.

Joel Sartore / Photo Ark / Brown mouse lemur (Microcebus rufus) portrait, Parc Botanique et Zoologique de Tsimbazaza, Madagascar. Captive.

David Pattyn / Russet-throated Puffbird (Hypnelus ruficollis) perched on branch, Tayrona National Park, Magdalena, Colombia.

Joel Sartore / Photo Ark / Russet angelfish (Centropyge potteri) portrait, Pure Aquariums. Captive, occurs in Pacific Ocean.

Joel Sartore / Photo Ark / Russet angelfish (Centropyge potteri) portrait, Pure Aquariums. Captive, occurs in Pacific Ocean.

David Fleetham / Potter's angelfish (Centropyge potteri) portrait, Hawaii, Pacific Ocean.

Doug Perrine / Male Potter's angelfish (Centropyge potteri) on reef, Pawai Bay, Hawaii, Pacific Ocean.

Doug Perrine / Male Potter's angelfish (Centropyge potteri) portrait, Pawai Bay, Hawaii, Pacific Ocean.

Doug Perrine / Male Potter's angelfish (Centropyge potteri) on reef, Pawai Bay, Hawaii, Pacific Ocean.

Doug Perrine / Male Potter's angelfish (Centropyge potteri) being cleaned of parasites by Hawaiian cleaner wrasse (Labroides phthirophagus), North Kona, Hawaii, Pacific Ocean.

Roland Seitre / Brown mouse lemur (Microcebus rufus) climbing down a tree trunk at night, Ranomafana National Park, Madagascar.

Roland Seitre / Brown mouse lemur (Microcebus rufus) on tree trunk at night, Ranomafana National Park, Madagascar.

David Fleetham / Potter's angelfish (Centropyge potteri) an endemic species, swimming over reef with various reef fish behind, Hawaii, Pacific Ocean.

Robert Thompson / Russet toughshank (Gymnopus dryophilus) toadstool cluster growing in forest floor, Ards Forest Park, County Donegal, Republic of Ireland, September.

Nick Upton / Bonnet pin mould (Spinellus fusiger) growing from cap of Russet toughshank mushroom (Collybia dryophila), GWT Lower Woods reserve, Gloucestershire, UK, October.

Nick Upton / Russet toughshank mushrooms (Collybia dryophila) emerging from rotting log, GWT Lower Woods reserve, Gloucestershire, UK, October.

Nick Upton / Russet toughshank mushrooms (Collybia dryophila) emerging from rotting log with one infected by Bonnet pin mould (Spinellus fusiger), GWT Lower Woods reserve, Gloucestershire, UK, October.

Nigel Cattlin / Citrus rust mite (Phyllocoptruta oleivora) blister damage visible on the upper side of lemon leaves, Sicily, Italy

Terry Whittaker / Brown mouse lemur (Microcebus rufus) in tree fork at night. Ranomafana National Park, Madagascar.

Nick Garbutt / Adult brown or rufus mouse lemur (Microcebus rufus) at night. Ranomafana National Park, south east Madagascar.

Nigel Cattlin / Russeting to apple fruit and bronzing to leaves by fruit tree red spider mite (Panonychus ulmi)