A polar bear enjoys a cool bath at the Schoenbrunn Zoo in Vienna, Austria, July 17, 2015. (Photo by Georg Hochmuth/EPA)

A Galapagos tortoise rests in a mud puddle in San Cristobal, Galapagos Islands, Ecuador, Wednesday, July 15, 2015. The islands are known for their endemic species and were studied by Charles Darwin and contributed to his theory of evolution by natural selection. UNESCO recognized the islands in 1978 as a World Heritage center. (Photo by Dolores Ochoa/AP Photo)

An Asian elephant swims a 65-meters long pool at Fuji Safari Park in Susono, at the foot of Mt. Fuji, southwest of Tokyo, Monday, July 13, 2015. The park was inspired by the images of elephants swimming in the ocean and wanted to build a facility exactly demonstrating what was little known in Japan that elephants can actually swim. (Photo by Koji Ueda/AP Photo)

A humpback whale breaches off the Long Beach Coast during a whale watching trip on The Harbor Breeze Cruises Triumphant in Long Beach, Saturday, July 11, 2015. (Photo by Nick Ut/AP Photo)

A chimpanzee eats an ice pop to cool off the summer heat in Shenyang, Liaoning province, July 12, 2015. (Photo by Reuters/China Daily)

A Madagascar lemur is seen during a hot summer day at the zoo in Spata near Athens, Greece July 16, 2015. Three weeks after capital controls were imposed on Greece's moribund banking system, supplies of the special imported dietary supplements needed to feed 2,200 animals from 345 species at Athens' only zoo are under threat. (Photo by Yiannis Kourtoglou/Reuters)

Turtles bask in the sun on a hot summer day at a zoo in Spata near Athens, Greece July 16, 2015. (Photo by Yiannis Kourtoglou/Reuters)

A seagull sits on a table next to a bottle of champagne in a hospitality area during the second round of the British Open golf championship on the Old Course in St. Andrews, Scotland, July 17, 2015. (Photo by Paul Childs/Reuters)

In this photograph released by Indian Gir National Park and Sanctuary Indian Deputy Conservator of Forests Sandeep Kumar taken on July 6, 2015 and released on July 16, 2015, newly-born Asiatic lion cubs sit near their den in the Khutani area of the sanctuary in the Junagadh region of Gujarat. The lion cubs were born on July 5, 2015. (Photo by AFP Photo/Gir National Park and Sanctuary Indian Deputy Conservator of Forests Sandeep Kumar)

Katielee Arrowsmith photographs a Lemur People take photos of Lemurs at Edinburgh Zoo's new walkway enclosure, Scotland on July 14, 2015. (Photo by Alan Simpson/REX Shutterstock)

An unnamed female baby elephant, born 12 July, find a protection zone by using the broad legs of her mother during a public debut in Hagenbecks Animal Park, Hamburg,northern Germany, 13 July 2015. (Photo by Daniel Bockwoldt/EPA/DPA)

An iguana races past near a landing strip at the eco-friendly Seymour of Baltra Airport, Galapagos Islands, Ecuador, Wednesday, July 15, 2015. (Photo by Dolores Ochoa/AP Photo)

A massive crocodile emerged from a lake in South Africa looking even more sinister than usual thanks to a layer of bright green slime covering its body. The huge reptile was swimming in the Kruger National Park when it emerged from the water caked in a layer of brightly-coloured algae. (Photo by Armand Grobler/Caters News)

Gertrud the chicken (L) walks with American rhea chicks in her enclosure at the Tierpark in Worms, Germany, 16 July 2015. The hen has taken over the task of rearing the chicks after the rhea cock actually responsible for their parental care absconded his responsibility. (Photo by Uwe Anspach/EPA)

In a Friday, July 10, 2015 photo, Keeper Shana Fredlake feeds a slice of squash to a Galapagos Tortoise at the Dallas Zoo. The Dallas Zoo's Animal Nutrition Center prepares animal diets daily for more than 2,000 animals at the zoo and the Children's Aquarium. (Photo by Smiley N. Pool/The Dallas Morning News via AP Photo)

In a Friday, July 10, 2015 photo, Dallas Zoo elephant Congo eats a half of a watermelon at the zoo. The Dallas Zoo's Animal Nutrition Center prepares animal diets daily for more than 2,000 animals at the zoo and the Children's Aquarium. (Photo by Smiley N. Pool/The Dallas Morning News via AP Photo)

A newborn harbor seal (phoca vitulina) baby swims with its mother Bobe at the animal park in Nyiregyhaza, 227 kms northeast of Budapest, Hungary, Friday, July 17, 2015. (Photo by Zsolt Czegledi/MTI via AP Photo)

A newborn harbor seal (Phoca vitulina) baby takes a swim in the Nyiregyhaza Animal Park in Nyiregyhaza, Hungary, 17 July 2015. The seal mother, Bobe, gave birth to the eight kilograms heavy and sixty centimeters long baby after a ten and a half months pregnancy. (Photo by Zsolt Czegeldi/EPA)

An Amur tiger (Panthera tigris altaica), also known as the Siberian tiger, sticks out its tongue at the zoo in Leipzig, Germany, Tuesday, July 14, 2015. (Photo by Jens Meyer/AP Photo)

Orangutan Bimbo relaxes at the zoo in Leipzig, Germany, Tuesday, July 14, 2015. (Photo by Jens Meyer/AP Photo)

Going nowhere in a hurry, this friendly Javan Tree frog can be seen casually hopping aboard the slow-paced snail who like a lonely highway trucker is only too happy to have the company. These cute critters chew the fat until froggy reaches his destination and alights at the top of the branch. Creative Designer and amateur photographer Kurit Afsheen (34) was able to capture this special sequence while out in his back garden in Ciledug, Indonesia. (Photo by Kurit Afsheen/Media Drum World)

A young Sumatran Orangutan (Pongo pygmaeus abeli) at the zoo in Zurich, Switzerland, 15 July 2015. (Photo by Patrick B. Kraemer/EPA)

Female Sumatran orangutan baby Pandai clinges to its mother “Xira” at the zoo in Zurich, Switzerland, on Wednesday, July 15, 2015. (Photo by Patrick B. Kraemer/Keystone via AP Photo)