Kumbuka, a 15-year-old western lowland gorilla, explores his new enclosure in the ZSL London Zoo, on May 2, 2013. The silverback male, who weights 407 pounds and stands seven foot tall, moved from Paignton Zoo two weeks ago. It is hoped that Kumbuka will mate with the zoo’s three female gorillas to increase numbers of the critically endangered species as part of the European breeding program. (Photo by Oli Scarff/Getty Images)


The trickdog Ben (C) performs during a press conference for the fair “dog and pet” in Dortmund, western Germany, on May 3, 2013. (Photo by Marius Becker/AFP Photo)


Ty, a Staffordshire Bull Terrier, is dressed as Superman by owner Anthony Farrante, on May 5, 2013. Enthusiasts gathered at the Picture House in Stratford, England, to parade their dogs dressed as famous Sci-Fi characters as part of a London-wide event called Sci-Fi London. (Photo by Jordan Mansfield/Getty Images)


Two cows challenge each other during the traditional spring release of cows that have spent the long winter months inside a cow-house, at the farm of Lasse and Sara Gillberg, at Bjorksattra farm in the Stockholm suburb of Huddinge, on May 5, 2013. (Photo by Klara Westblom/Scanpix Sweden)


A baby monkey, a lion cub and tiger cubs play at the Guaipo Manchurian Tiger Park in Shenyang, Liaoning Province, May 1, 2013. (Photo by Reuters/Stringer)

A one-month-old Eurasian griffon sits next to its mother in their nest at the Zoo of Duisburg, Germany, on May 3, 2013. (Photo by Federico Gambarini/Associated Press)


Great white pelicans play in the Dresden Zoo in eastern Germany, on April 29, 2013 (Photo by Jens Meyer/AP Photo)


A red panda eats the leaves of a bamboo plant at the Zoo in Krefeld, Germany, 29 April 2013. (Photo by Roland Weihrauch/EPA)


A new arrival at Fota wildlife park, a baby Bison, with mother Donna, May 1, 2013. The park are looking for the public’s help to name the recently born male. The calf born on Saturday is the latest Bison born in the park, which has included 3 calves that returned to the wild in Poland in 1998. (Photo by Neil Danton)


Lioness Tia licks one of her cubs as they huddle close together in their enclosure at Emmen Zoo in the Netherlands on April 27, 2013. The four cubs were born on April 7. (Photo by Catrinus Van Der Veen/EPA)


A 7-year-old white tiger sits with one of her cubs at Tobu Zoo in Miyashiro, near Tokyo, Thursday, May 2, 2013. Four newborn white tiger cubs made their first public appearance at the Zoo on Thursday. The four cubs – one female and three males – were born 46 days ago. (Photo by Koji Sasahara/AP Photo)


A young ring-tailed lemur with his mother in their enclosure in Wroclaw’s Zoo in Wroclaw, Poland, 27 April 2013. Five lemurs were born two weeks ago at the Zoo. (Photo by Maciej Kulczynski/EPA)


A dog wrapped in a jacket, belonging to a street artist, sits on a pavement in London April 22, 2013. An influential academic paper which made the case for austerity, is thought to be flawed. The paper, called “Growth in a Time of Debt” by Harvard professors, Carmen Reinhart and Ken Rogoff, has data missing, according to Universtiy of Massachusetts student, Thomas Herndon. (Photo by Stefan Wermuth/Reuters)


A breeder, whose business has been affected by the H7N9 bird flu virus, walks his ducks along a road in Changzhou county, Shandong province, on April 25, 2013. A dropoff in Chinese demand for soybeans used to feed poultry and livestock could last for months, as consumers lose their appetite for poultry in response to a deadly bird flu virus outbreak and amid lingering images of rotting pig carcasses floating in a river. (Photo by Reuters/Stringer)


Baby gorilla born at the Burger’s Zoo in Arnhem (Netherlands), relax on the lap of her mother on the lawn, on April 25, 2013. (Photo by Action Press/Honopix/Estadão Conteúdo)


This picture taken on April 18, 2013 shows a white lion cub in his pen at the Pont-Scroff’s Zoo in Pont-Scorff, western France. Three lion cubs, two males and a female, were born on February 23 and were shown for the first time to the public on April 17. (Photo by Fred Tanneau)


“Dimbi”, a blue-eyed black lemur cub (Eulemur flavifrons) is pictured at the zoo of Mulhouse, northeastern France, on April 19, 2013. There’s currently less than 2,000 blue-eyed black lemurs into the wild. (Photo by Sebastien Bozon/AFP Photo)