View of the “Sunset Lake” hot spring with it's unique colors caused by brown, orange and yellow algae-like bacteria called Thermophiles, that thrive in the cooling water turning the vivid aqua-blues to a murkier greenish brown, in the Yellowstone National Park, Wyoming on June 1, 2011. Yellowstone National Park, was established by the U.S. Congress and signed into law by President Grant on March 1, 1872. The park is located primarily in the U.S. state of Wyoming, though it also extends into Montana and Idaho and was the first national park in the world. It is known for its wildlife and its many geothermal features, especially the Old Faithful Geyser. (Photo by Mark Ralston/AFP Photo)

Photographer Andy Hall joins the thousands of fans from west Africa who have gathered for Baaba Maal's annual Blues du Fleuve festival in Senegal. Here: Dancers wait to perform on stage. (Photo by Andy Hall/The Observer)

Brave photographer Masa Ushioda captured the shots of this wild gator in vast marsh land in the Everglades National Park, in Florida, USA. He said: “Bright sunlight and blue sky were critical elements in this picture – in addition to getting a wild 10-foot alligator in the middle of the viewfinder with a perfect angle”.

New York to photograph some of the city’s best-humored taxi drivers. These drivers put a face to one of the most dedicated workforces in NYC, driving day and night to transport New Yorkers and our guests alike. This year’s calendar features three returning All-Stars and 8 new drivers, and debuts our first ever husband and wife driving duo.

In this handout image provided by the European Space Agency (ESA) and NASA, the International Space Station and the docked space shuttle Endeavour orbit Earth during Endeavour's final sortie on May 23, 2011 in Space. Italian astronaut Paolo Nespoli captured the first-ever images of an orbiter docked to the International Space Station from the viewpoint of a departing vessel as he returned to Earth in a Soyuz capsule. (Photo by Paolo Nespoli - ESA/NASA via Getty Images)

An Israeli jail authority officer escorts a prison van containing Palestinian prisoners as it enters Hasharon jail on October 16, 2011 in Tel Mond, Israel. IDF soldier Gilad Shalit is to be freed from 5 years of captivity in Gaza in an exchange deal which will see the release of 477 Palestinian prisoners in an initial deal with another 550 to freed after the return of Shalit. (Photo by Uriel Sinai/Getty Images)

Visitors enjoy watching the Blue Nemophila flowers bloom during the Golden Week holidays, at Hitachinaka Kaihin Park on May 02, 2010 in Hitachinaka, Ibaraki, Japan. Millions of nemophilas blossom across the “Miharashi No Oka” hill at Hitachi Seaside Park for the annual “Nemophila Harmony” flower festival. (Photo by Koichi Kamoshida/Getty Images)

“The Red-eyed Treefrog (Agalychnis callidryas) is an arboreal hylid native to Neotropical rainforests in Central America. Red-eyed tree frogs, as their name states, have red eyes with vertically narrowed noses, a vibrant green body with yellow and blue vertically striped sides, and orange or yellow webbed feet and toes”. – Wikipedia. (Photo by Donald Quintana)