Shane Gross / Invasive Lionfish (Pterois volitans) which have taken over and are wiping out native fish in the Atlantic ocean. The highest densities are in the northern gulf of Mexico. Destin, Florida, USA.

Shane Gross / Invasive Lionfish (Pterois volitans) which have taken over and are wiping out native fish in the Atlantic ocean. The highest densities are in the northern gulf of Mexico. Destin, Florida, USA.

Jeff Foott / The Citadel Ruins, Cedar Mesa area, Bears Ears National Monument, Utah

Kristel Richard / An Indian cowboy has lost his balance from a bronc or wild paint horse during the All Indian Rodeo, at the annual Indian Crow Fair, at Crow Agency, near Billings, Montana, USA, August 2011, Sequence 3...

Jeff Vanuga / Native American Teepee rings on Table Mountain near Dubois, Shoshone reserve, Wyoming, USA, May 2009

Rob Tilley / Rock engravings of the native american Pueblo people, Chaco Culture National Historical Park, New Mexico, USA, February 2009

ZSSD / African Hedgehog (Atelerix algirus) baby next to American dime to show scale, native to Africa

Jim Brandenburg / Inuits dog sledding in midnight sun, Ellesmere Island, Nunavut, Canada

Norbert Wu / American Paddlefish (Polyodon spathula) can sense electrical fields with long paddle, native to Mississippi River drainage system

Nigel Cattlin / Yellow trumpet pitcherplant (Sarracenia flava) flower and insect trapping pitcher. Native to USA.

John Cancalosi / House sparrow (Passer domesticus) male flying from nest in Saguaro (Carnegiea gigantea) cactus. Non-native bird species that competes with native species for nesting cavities in cacti. Sonoran desert,...

John Cancalosi / House sparrow (Passer domesticus) male at nest in Saguaro (Carnegiea gigantea) cactus cavity. Non-native bird species that competes with native species for nesting cavities in cacti. Sonoran desert, A...