Rolf Nussbaumer / RF- Western Diamondback Rattlesnake (Crotalus atrox), adult in striking pose with rattle raised, in wildflowers. Laredo, Webb County, South Texas, USA. April. (This image may be licensed either as rig...

Rolf Nussbaumer / RF- Sword-billed Hummingbird (Ensifera ensifera) female feeding from Passion flower (Passiflora mixta). Papallacta, Ecuador, Andes, South America. January. (This image may be licensed either as rights...

Staffan Widstrand / RF- Pale throated sloth (Bradypus tridactylus) clinging to tree. Manaus, Brazil. (This image may be licensed either as rights managed or royalty free.)

Nick Garbutt / RF - Red-and-Green Macaws or Green-winged Macaws (Ara chloropterus) in flight over forest canopy. Buraco das Araras (Sinkhole of the Macaws), Jardim, Mato Grosso do Sul, Brazil. September. (This image...

Nick Garbutt / RF - Red-and-green macaws (Ara chloropterus) two with one taking off, Buraco das Araras (Sinkhole of the Macaws), Jardim, Mato Grosso do Sul, Brazil. September. (This image may be licensed either as...

Nick Garbutt / RF - Pair of Red-and-green macaws (Ara chloropterus) preening. Buraco das Araras (Sinkhole of the Macaws), Jardim, Mato Grosso do Sul, Brazil. September. (This image may be licensed either as rights...

Nick Garbutt / RF - Andean condor (Vultur gryphus) flying over Torres del Paine Massif. Torres del Paine National Park, Chilean Patagonia, Chile. March. (This image may be licensed either as rights managed or royalt...

Nick Garbutt / RF - Adult Giant Anteater (Myrmecophaga tridactyla) foraging. Southern Pantanal, Moto Grosso do Sul State, Brazil. September. (This image may be licensed either as rights managed or royalty free.)

Carol Walker / RF - Wild Mustang mare with sister and foal at Black Hills Wild Horse Sanctuary, South Dakota, USA. May. (This image may be licensed either as rights managed or royalty free.)

Carol Walker / RF - Wild black Mustang filly leaping as pinto Mustang mother and friend follow, Black Hills Wild Horse Sanctuary, South Dakota, USA. June. (This image may be licensed either as rights managed or roy...

Carol Walker / RF - Head portrait of wild Mustang stallion tossing his mane while running, Black Hills Wild Horse Sanctuary, South Dakota, USA. February. (This image may be licensed either as rights managed or royal...

Carol Walker / RF - Two wild Mustang stallions meeting in trees, Carrott Island, South Carolina, USA. (This image may be licensed either as rights managed or royalty free.)

Carol Walker / RF - Wild pinto Mustang stallion running in snow, Black Hills Wild Horse Sanctuary, South Dakota, USA. January. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Gliding tree frog (Agalychnis spurrelli) captive, occurs in Colombia, Costa Rica, Ecuador, and Panama. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Marine Iguana (Amblyrhynchus cristatus) head portrait, Fernandina island, Galapagos, Ecuador. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Yellow-bellied sapsucker (Sphyrapicus varius) female feeding at sap well. Dinero, Lake Corpus Christi, South Texas, USA. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Paper wasp (Polistes sp) adult in flight over vivid yellow flowers. Dinero, Lake Corpus Christi, South Texas, USA. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Northern cardinal (Cardinalis cardinalis) male perched in ice covered bush. Dinero, Lake Corpus Christi, South Texas, USA. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Black-necked stilt (Himantopus mexicanus) four adults standing in water with one in flight. Dinero, Lake Corpus Christi, South Texas, USA. (This image may be licensed either as rights managed or r...

Rolf Nussbaumer / RF- Western Diamondback Rattlesnake (Crotalus atrox), adult in striking pose. Laredo, Webb County, South Texas, USA. April. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Cane toad / Marine toad / Giant toad (Bufo marinus) adult with Great plains narrowmouth toad (Gastrophryne olivacea) sitting on its head. Laredo, Webb County, South Texas, USA. (This image may be...

Rolf Nussbaumer / RF- Common Poorwill (Phalaenoptilus nuttallii) adult on nest camouflaged. South Texas, USA. April. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Cane Toad / Marine Toad / Giant Toad (Bufo marinus) adult in Dogweed (Dyssodia pentachaeta). Laredo, Webb County, South Texas, USA. April. (This image may be licensed either as rights managed or r...

Rolf Nussbaumer / RF- Young Western coachwhip (Masticophis flagellum testaceus). Laredo, Webb County, South Texas, USA. April. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Trecul Yucca, Spanish Dagger (Yucca treculeana), blossom with night stars. Laredo, Webb County, South Texas, USA. April. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Dung Beetle (Scarabaeinae) adults rolling dung ball. Laredo, Webb County, South Texas, USA. April. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Blue Footed Booby (Sula nebouxii) perched on rock. Post Office Bay, Champion Island, Galapagos, Ecuador. April. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Portrait of Galapagos Land Iguana (Conolophus subcristatus) resting. Baltra, Galapagos, Ecuador. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Portrait of a Galapagos Giant Tortoise (Chelonoidis nigra), captive. Santa Cruz Island, Galapagos, Ecuador. April. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Close up of Paper Wasp (Polistes sp.) on nest, Fennessey Ranch, Refugio, Coastal Bend, Texas Coast, USA. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Northern Cardinal (Cardinalis cardinalis) male perched on branch of flowering Eastern Redbud (Cercis canadensis). Dinero, Lake Corpus Christi, South Texas, USA. (This image may be licensed either...

Edwin Giesbers / RF- Chacoan horned frog (Ceratophrys cranwelli) captive, from South America. (This image may be licensed either as rights managed or royalty free.)

Rolf Nussbaumer / RF- Green-crowned Brilliant hummingbird (Heliodoxa jacula) adult feeding. Mindo, Ecuador, Andes, South America. February. (This image may be licensed either as rights managed or royalty free.)

Carol Walker / RF- Group of Chinstrap Penguins (Pygoscelis antarctica) on ice. South Orkney Islands. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Rainforest butterfly (Papilio sp) feeding on minerals from mud. Brazil, South America. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Yacaré caiman (Caiman yacare) close up of open mouth. Pantanal, Brazil. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Close up of Piranha teeth (Serrasalmus). Pantanal, Brazil. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / Burrowing owl portrait (Athene cunicularia) on fence post. Pantanal, Brazil Mato Grosso. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Male Jaguar in undergrowth (Panthera onca) captive. Pantanal, Brazil. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Black / Jacare caiman (Caiman niger) head portrait with open mouth. Pantanal, Brazil. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Toco toucan feeding in tree (Ramphastos toco). Pantanal, Mato Grosso, Brazil. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Portrait of Giant tortoise (Geochelone elephantopus). Galapagos National Park, Ecuador. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Iguazu falls Brazil / Argentina border. Iguassu, South America. (This image may be licensed either as rights managed or royalty free.)