Male black grouse (Lyrurus tetrix) fighting on snow covered field, Finland

Male Great frigatebird (Fregata minor) in breeding plumage with red gular pouch, on Genovesa (Tower) Island, Galapagos Islands, UNESCO World Heritage Site, Ecuador, South America

A juvenile red-footed booby (Sula sula), in its white color morph plumage in flight over the ocean in Palau, Micronesia, Pacific

Adult black guillemot (Cepphus grylle) in summer plumage near Vigur Island in Isafjardardjup Bay, Iceland

Adult male Magellan goose (upland goose) (Chloephaga picta), on New Island in the Falkland Islands, South Atlantic Ocean, South America

Brunnich's guillemot (Uria lomvia) breeding and nesting site at Cape Fanshawe in the Svalbard Archipelago, Norway, Arctic, Europe

Black-browed albatross (Thalassarche melanophrys) close-up at breeding colony on Carcass Island in the Falkland Islands

Adult yellow warbler (Dendroica petechia aureola) in the Galapagos Island Archipelago, UNESCO World Heritage Site, Ecuador, South America

Researcher setting up a net to capture hummingbirds as part of a pollination study, rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

Rufous-tailed Hummingbird (Amazilia tzacatl) in a net set up by a researcher as part of a pollination study, rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

Researcher catching Rufous-tailed Hummingbird (Amazilia Tzacatl) in a net set up for pollination study, rainforest at "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

Researchers picking up pollen using tape on the beak of a Rufous-tailed hummingbird as part of a pollination study, rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

Researchers picking up pollen with a brush from the beak of a Rufous-tailed hummingbird as part of a pollination study, rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui , Costa Rica

Researcher measuring the beak of a Rufous-tailed hummingbird as part of a pollination study, rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

Researchers picking up pollen with a brush from the beak of a hummingbird Stripe-throated Hermit as part of a pollination study, rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

Researcher measuring a 2.6 gram Stripe-throated Hermit hummingbird wing as part of a pollination study, rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica

Researcher photographing a 2.6 gram Stripe-throated Hermit hummingbird as part of a pollination study, rainforest at the "La Selva" research station in Puerto Viejo de Sarapiqui, Costa Rica