Paul Hobson / Rufous motmot (Baryphthengus martii) perched on branch. Rancho Naturalista, Cartago, Costa Rica.

Donald M. Jones / Rufous Hummingbird (Selasphorus rufus) female feeding on flower nectar, Montana

Hermann Brehm / Nightingale (Luscinia megarhynchos ) singing, Germany, April.

David Perpinan / Great rufous woodcreeper (Xiphocolaptes major) arriving at nest site in a dead palm tree, climbs down to nest, Pantanal, Mato Grosso do Sul, Brazil.

Murray Cooper / Minden / Rufous-tailed Jacamar (Galbula ruficauda), South America

Murray Cooper / Rufous-tailed Jacamar (Galbula ruficauda), South America

Thomas Marent / Cotton-top Tamarin (Saguinus oedipus) with red pollen after feeding on flower nectar, Tayrona National Natural Park, Colombia

David Tipling / Nightingale (Luscinia megarhynchos) singing, Camargue Provence France May

Greg Oakley/ BIA / Rufous Whistler (Pachycephala rufiventris) male calling, Victoria, Australia

Andres M. Dominguez / Rufous-tailed scrub robin (Cercotrichas galactotes) perched on grape vine, Sevilla, Spain, August.

Gerrit Vyn / Red-necked stint (Calidris ruficollis) on its Russian breeding grounds. Chukotka, Russia. June.

Tim Zurowski / Rufous Hummingbird (Selasphorus rufus) female feeding on flower nectar, British Columbia, Canada

Laurent Geslin / Rufous / Indian tree pie {Dendrocitta vagabunda} searching for insects on Spotted deer (Axis axis) Sariska reserve, Rajasthan, India

Mark MacEwen / Rufous elephant shrew (Elephantulus rufescens) Tuli Block, Botswana

Konstantin Mikhailov / The upper forest belt in Altai Mountains after first snowfall, Katunsky Range with Siberian larch trees (Larus sibirica rufous) and Siberian pine trees (Pinus sibirica) Mt.Belukha Nature park, South-...

Diane McAllister / Rufous hummingbird (Selasphorus rufus) drinking nectar from an Agastache bloom in a backyard in Reno. Nevada, USA, August

Tim Laman / Rufous-sided sticky frog (Kalophrynus pleurostigma) on the ground in the lowland rainforest, Bako National Park, Sarawak, Borneo, Malaysia

Donald M. Jones / Rufous Hummingbird (Selasphorus rufus) male sitting on willow branch, Troy, Montana

Tim Laman / Rufous-necked hornbill (Aceros nipalensis) perched on branch, Huai Kha Khaeng Wildlife Sanctuary, Thailand. IUCN Vulnerable

Tim Laman / Various seeds of rainforest trees regurgitated by Rufous-necked Hornbill (Aceros nipalensis). Huai Kha Khaeng Wildlife Sanctuary, Thailand.

Thomas Marent / Cotton-top Tamarin (Saguinus oedipus) in tree, northern Colombia

Bernard Castelein / Rufous / Indian treepie {Dendrocitta vagabunda} searching for insects on deer, Panna NP, Madhya Pradesh, India

Luiz Claudio Marigo / Rufous hornero / Ovenbird at mud nest {Furnarius rufus} Mato Grosso, Brazil

Luiz Claudio Marigo / Rufous tailed jacamar {Galbula ruficauda} Beni, Bolivia

Gabriel Rojo / Rufous collared sparrow {Zonotrichia capensis} El Condorito NP, Argentina

Tom Vezo / Rufous Hummingbird (Selasphorus rufus) male feeding at flower, Green Valley, Arizona

Claus Meyer / Cotton-top Tamarin (Saguinus oedipus), Colombia

Michael & Patricia Fogden / Eyelash Viper (Bothriechis schlegelii) gold morph lying in wait on Heliconia (Heliconia imbricata) to strike at Rufous-tailed Hummingbird (Amazilia tzacatl) rainforest, Costa Rica

Michael & Patricia Fogden / Rufous-tailed Hummingbird (Amazilia tzacatl) feeding on Hamelia flowers, Costa Rica

Tom Vezo / Red-tailed Hawk (Buteo jamaicensis) adult rufous morph flying, Sulphur Springs Valley, Arizona

Tim Fitzharris / Rufous Hummingbird (Selasphorus rufus) juvenile feeding on flowers, New Mexico

Tim Fitzharris / Rufous Hummingbird (Selasphorus rufus) feeding on flowers, New Mexico

Tim Fitzharris / Rufous Hummingbird (Selasphorus rufus) feeding on the nectar of a Desert Figwort (Scrophularia desertorum), New Mexico

Loic Poidevin / Rufous-naped Lark (Mirafra africana) standing in grass, Masai Mara, Kenya. March.

Staffan Widstrand / Wild Wonders of China / Rufous-throated Partridge (Arborophila rufogularis) Gaoligongshan, Yunnan, China

Staffan Widstrand / Wild Wonders of China / Rufous-throated Partridge (Arborophila rufogularis) Gaoligongshan, Yunnan, China

David Tipling / Nightingale (Luscinia megarhynchos) male singing, Lodge Hill, Kent, May

David Tipling / Nightingale (Luscinia megarhynchos) male in song, Lodge Hill, Kent, May

David Tipling / Nightingale (Luscinia megarhynchos) Lodge Hill, Kent, May

Dong Lei / Rufous-necked snowfinch (Pyrgilauda ruficollis) with insects in beak, feeding chicks at nest in rock hollow. Sanjiangyuan National Nature Reserve, Qinghai Province, Qinghai-Tibet Plateau, China. Augus...

Dong Lei / Rufous-necked snowfinch (Pyrgilauda ruficollis) adult with begging chicks. Sanjiangyuan National Nature Reserve, Qinghai Province, Qinghai-Tibet Plateau. August.

Dong Lei / Rufous-necked snowfinch (Pyrgilauda ruficollis) adult with begging chicks at nest in rock hollow. Sanjiangyuan National Nature Reserve, Qinghai Province, Qinghai-Tibet Plateau. August.

Gabriel Rojo / Rufous hornero (Furnarius rufus) with prey in beak, on top of mud nest. Pantanal, Mato Grosso, Brazil.

Gabriel Rojo / Rufous hornero (Furnarius rufus) on top of mud nest. Pantanal, Mato Grosso, Brazil.

Ingo Arndt / Rufous-tailed hummingbird (Amazilia tzacatl) nectaring on flower. Western slope of Andes, Ecuador. October.

Rick Price / Nankeen night heron (Nycticorax caledonicus) standing on log. Ord River, The Kimberley, Western Australia.

Oscar Dewhurst / Rufous-collared sparrow (Zonotrichia capensis) on stone pavement. Cusco, Peru. February

Staffan Widstrand / Rufous treepie (Dendrocitta vagabunda) Keoladeo Ghana National Park, Bharatpur, Rajasthan, India

John Shaw / Rufous-tailed hummingbird (Amazilia tzacatl) with heliconia plants adding color in the background. San Jose, Costa Rica, December.

Bernard Castelein / Rufous-tailed jacamar, (Galbula ruficauda), female, perched on twig, Municipal protected area of Pampas del Yacuma, Bolivia

Bernard Castelein / Rufous-tailed jacamar (Galbula ruficauda) perched, Pampas del Yacuma Protected Area, Bolivia

David Pattyn / Rufous-tailed Hummingbird (Amazilia tzacatl) male flying, Mindo Cloud Forest, Ecuador, July

Nick Upton / Lesser short-toed lark (Calandrella rufescens) perched on a rock in steppe grassland, Teguise Plain, Lanzarote Canary Islands, February.

Karine Aigner / Rufous-legged owl (Strix rufipes) at the Akiba Fukurou Owl Cafe, Tokyo, Japan

Paul Hobson / Rufous motmot (Baryphthengus martii) perched on branch. Rancho Naturalista, Cartago, Costa Rica.

Thomas Marent / Rufous-breasted Chat-Tyrant (Ochthoeca rufipectoralis), Selva de Ventanas Natural Reserve, Colombia

Thomas Marent / Rufous-breasted Chat-Tyrant (Ochthoeca rufipectoralis), Selva de Ventanas Natural Reserve, Colombia

Thomas Marent / Rufous-tailed Hummingbird (Amazilia tzacatl) feeding on flower nectar, Valle del Cauca, Colombia

Thomas Marent / Rufous-tailed Hummingbird (Amazilia tzacatl) feeding on flower nectar, Valle del Cauca, Colombia

Thomas Marent / Rufous-tailed Hummingbird (Amazilia tzacatl), Valle del Cauca, Colombia

Thomas Marent / Rufous-tailed Hummingbird (Amazilia tzacatl), Valle del Cauca, Colombia

Thomas Marent / Rufous-collared Sparrow (Zonotrichia capensis), Tatama National Park, Colombia

Thomas Marent / Rufous-tailed Hummingbird (Amazilia tzacatl) calling, Tatama National Park, Colombia

Andy Rouse / Rufus-breasted Hermit hummingbird (Giaucis hirsutus) female hovering, Tobago

Ingo Arndt / Rufous-tailed Hummingbird (Amazilia tzacatl) feeding on heliconia flower nectar, Andes western slope, Ecuador

Steven David Miller / Nankeen / Rufous night heron (Nycticorax caledonicus) perched in Eucalyptus tree. North Queensland, Australia.

Steven David Miller / Nankeen / Rufous night heron (Nycticorax caledonicus) perched in Eucalyptus tree. North Queensland, Australia.

Philippe Clement / Rufous hornbill (Buceros hydrocorax) endemic to the Philippines, captive, digital composite

Philippe Clement / Parasite fly / tachinid fly (Tachina fera) feeding on nectar from Hogweed (Heracleum sphondylium) in summer, France. August.

Glenn Bartley/ BIA / Rufous-tailed Hummingbird (Amazilia tzacatl) on nest, Andes, Colombia

Naskrecki & Guyton / Rufous mouse-eared bat (Myotis bocagii) in flight, against white background, Mozambique.

Philippe Clement / Tachina flies (Tachina fera) nectaring on Umbellifer (Apiaceae) flowers in summer, Luxembourg, August.

David Perpinan / Great rufous woodcreeper (Xiphocolaptes major) entering its nest in a dead palm tree, Pantanal, Mato Grosso do Sul, Brazil.

David Perpinan / Great rufous woodcreeper (Xiphocolaptes major) startled whilst incubating eggs, Pantanal, Mato Grosso do Sul, Brazil.

David Perpinan / Great rufous woodcreeper (Xiphocolaptes major) looking inside a dead palm tree for a nest site, Pantanal, Mato Grosso do Sul, Brazil.

David Perpinan / Great rufous woodcreeper (Xiphocolaptes major) arriving at dead palm tree containing its nest, Pantanal, Mato Grosso do Sul, Brazil.

Piotr Naskrecki / Rufous mouse-eared bat (Myotis bocagii) in flight, Bela Vista, Gorongosa National Park, Sofala, Mozambique. Controlled conditions

Karine Aigner / Portrait of a Eastern towhee (Pipilo erythrophthalmus) with white background, Block island, Rhode Island, USA. Bird caught during scientific research.

Staffan Widstrand / Wild Wonders of China / Rufous-bellied niltava (Niltava sundara) bird sitting on a branch , Tangjiahe National Nature Reserve, Qingchuan County, Sichuan province, China

Staffan Widstrand / Wild Wonders of China / Rufous-gorgeted flycatcher (Ficedula strophiata) sitting on a branch , Tangjiahe National Nature Reserve, Qingchuan County, Sichuan province, China

Staffan Widstrand / Wild Wonders of China / Rufous-gorgeted flycatcher (Ficedula strophiata) sitting on a branch , Tangjiahe National Nature Reserve, Qingchuan County, Sichuan province, China

Felis Images / Long-tailed shrike (Lanius schach) perched on branch, India.

Joao Burini / Rufous headed tanager (Hemithraupis ruficapilla) male, Intervales State Park, Sao Paulo, Atlantic Forest South-East Reserves, UNESCO World Heritage Site, Brazil.

Alan Murphy/ BIA / Rufous-winged Sparrow (Peucaea carpalis) calling, Arizona

Alan Murphy/ BIA / Rufous-winged Sparrow (Peucaea carpalis), Arizona

Avi Meir/ BIA / Rufous-tailed Wheatear (Oenanthe xanthoprymna) male, Arabah, Israel

Avi Meir/ BIA / Rufous-tailed Wheatear (Oenanthe xanthoprymna) male, Arabah, Israel

Andy Trowbridge / Red-necked Stint (Calidris ruficollis) in breeding plumage, foraging in shallow water. Lake Ellesmere, New Zealand. November.

Andy Trowbridge / Non-breeding plumaged Red-necked Stint (Calidris ruficollis) standing in shallow water. Lake Ellesmere, New Zealand. November.

Eric Sohn Joo Tan/ BIA / Rufous-throated Partridge (Arborophila rufogularis), Yunnan, China

David Pattyn / Madagascar pygmy kingfisher (Corythornis madagascariensis) at night. Masoala National Park, Bay of Angotil, North eastern Madagascar.

David Pattyn / Madagascar pygmy kingfisher (Corythornis madagascariensis) feeding, with beak covered in dirt, Masoala National Park, Bay of Angotil, North eastern Madagascar.

Konrad Wothe / Rufous-tailed Hummingbird (Amazilia tzacatl) feeding on flower nectar, Ecuador

Konrad Wothe / Rufous-tailed Hummingbird (Amazilia tzacatl), Ecuador

Lucas Bustamante / Buff-tailed coronet (Boissonneaua flavescens) and female Rufous booted racket tail (Ocreatus underwoodii addae) fighting in flight, Mashpi, Pichincha, Ecuador.

Lucas Bustamante / Rufous-eyed stream frog (Duellmanohyla rufioculis) on plant,. Siquirres, Limon, Costa Rica.