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