Firefighters pull a pig as they try to rescue it from a well at a pig farm in Huanghua township of Leqing, Zhejiang province, April 25, 2014. Seven local firefighters successfully rescued a 300 kg (661 lbs) pig which fell down a well on Friday morning, local media reported. (Photo by Reuters/China Daily)

A sheep with dyed pink wool grazes in a field near the village of Balintoy April 24, 2014. It has been painted pink to welcome the arrival of the Giro d'Italia cycle race whose race leader wears a pink jersey. (Photo by Cathal McNaughton/Reuters)

Friends and neighbors of the late Douglas Rafael da Silva Pereira pray before playing soccer in a plaza near the spot where Silva Pereira's body was found in the Pavao Pavaozinho slum of Rio de Janeiro, Brazil, Wednesday, April 23, 2014. On Tuesday night, angry residents who blame police for his death set fires and showered homemade explosives and glass bottles onto a busy avenue in the city's main tourist zone following the killing of the popular local figure. (Photo by Felipe Dana/AP Photo)

Tourists prepare to snorkel at a beach at Rang island near Kut island, eastern Thailand, April 24, 2014. (Photo by Athit Perawongmetha/Reuters)

People watch a traditional bullfight in the village of Sestanovac, in south Croatia April 21, 2014. Judges check for bulls with sharpened horns, which are then disqualified before the start of each bullfight to prevent any serious injury among the animals. Traditional bullfights are watched by thousands in south Croatia. (Photo by Antonio Bronic/Reuters)

A polar bear cub (L) plays with its mother Uslada at the Leningrad Zoo in St. Petersburg, April 24, 2014. The four-month old polar bear cub, who made its first public appearance on Thursday , is yet to be named. (Photo by Alexander Demianchuk/AFP Photo)

Spectacled bear mother Cashu holds her cub at the zoo in Frankfurt Main, Germany, 17 April 2014. Two bear cubs have taken their first excursion of their enclosure. (Photo by Boris Roessler/EPA)

A lamb cuddles with its mother on the Ems dike near Leer, Germany, 18 April 2014. Lamb is a traditional dish at Easter. (Photo by Ingo Wagner/EPA)

Young ring-tailed lemurs (Lemur catta) cling to their mother in their enclosure in Wroclaw's Zoo, in Wroclaw, Poland, 18 April 2014. The primate is endemic to the island of Madagascar. (Photo by Maciej Kulczynski/EPA)

A child looks at a squirrel at the Royal Lazienki Park in Warsaw, on Easter Monday, Poland, 21 April 2014. (Photo by Grzegorz Jakubowski/EPA)

Vlad Duric escapes serious injury after falling off Golfing in in the home straight in Race 5, the Bert Bryant Handicap during Melbourne Racing at Caulfield Racecourse on April 19, 2014 in Melbourne, Australia. Duric walked away with a minor leg injury. (Photo by Vince Caligiuri/Getty Images)

A bird perches inside the barrel of one of two Soviet T-34 tanks in a Soviet War Memorial on April 22, 2014 in Berlin, Germany. German politicians have condemned a petition launched last week by the B.Z. newspaper as well as the country's best-selling tabloid, Bild, which encouraged readers to send letters of protest to the federal parliament demanding the removal of the tanks located in the Soviet War Memorial in the city's central Tiergarten Park located near the Brandenburg Gate, erected by the Soviet Union to commemorate the 80,000 Soviet Armed Forces soldiers who died during the Battle of Berlin in 1945. An extract of the petition reads, in explanation, that the tanks do not belong in such a prominent position “in an era when Russian tanks are threatening a free and democratic Europe”. (Photo by Adam Berry/Getty Images)

A bird perches inside the barrel of one of two Soviet T-34 tanks in a Soviet War Memorial on April 22, 2014 in Berlin, Germany. (Photo by Adam Berry/Getty Images)

A cow looks into the photographers camera on April 23, 2014, near Puergen, southern Germany. Meteorologists forecast temperatures around 20 degrees for the coming days in southern Germany. (Photo by Nicolas Armer/AFP Photo/DPA)

Prince William and Catherine, Duchess of Cambridge, feed giraffes at Sydney's Taronga Zoo April 20, 2014. The Prince and his wife Kate are undertaking a 19-day official visit to New Zealand and Australia with their son George. (Photo by Chris Jackson/Reuters)

Marwan Elboury takes his three year old pet Rouen French ducks, Donald and Daffy for a walk along Rye Lane in south London on April 25, 2014. Marwin, 20, works at The Garden Centre Aquatics in Peckham, London. (Photo by John Stillwell/PA Wire)

Unnamed and recently newborn lemur twins cling to their mum, 19-year-old Roxy, at Wild Place Project in Bristol on April 23, 2014, where three of the female lemurs in the specially created walk-through enclosure have had babies over the last two weeks. (Photo by Ben Birchall/PA Wire)

In this photo provided by Six Flags Discovery Kingdom, Lily, a three-day-old Pacific harbor seal pup, swims at Six Flags Discovery Kingdom in Vallejo, Calif., Tuesday, April 22, 2014. The 20-lb. black, grey and white spotted seal pup was born on April 19 at the park's Seal Cove exhibit. Pups double their weight within the first four to six weeks, nursing on the rich mother's milk, which is about 45 percent fat, and then is weaned. (Photo by Nancy Chan/AP Photo/Six Flags Discovery Kingdom)

Participants prepare to take part in the annual “London Harness Horse Parade” on Easter Monday at The South of England Centre on April 21, 2014 in Ardingly, England. The parade of harnessed horses, ponies and donkeys attracts exhibitors from across the UK and Ireland who are judged on numerous criteria in the hope of receiving a First Class award. The historic Parade is an amalgamation of the London Cart Horse Parade, founded in 1885, and the London Van Horse Parade, founded in 1904. (Photo by Oli Scarff/Getty Images)

A trio of wild fox cubs cautiously exit their den near a farm road in Northampton County, Va. on Thursday evening, April 24, 2014. (Photo by Jay Diem/AP Photo/Eastern Shore News)

An Afghan youth stands on top of a buffalo as they cross a river on the outskirts of Jalalabad on April 21, 2014. Afghanistan remains at war, with civilians among the hardest hit as the Taliban wage an increasingly bloody insurgency against the government. (Photo by Noorullah Shirzada/AFP Photo)

Baby gorilla Jengo play's with the hand of female adult gorilla Kumili at the zoo in Leipzig, Germany, Thursday, April 24, 2014. The baby gorilla Jengo was born on December 2, 2013. (Photo by Jens Meyer/AP Photo)

Baby gorilla Jengo, left, stands next to Diara and her mother Kumili at the zoo in Leipzig, Germany, Thursday, April 24, 2014. The baby gorilla Jengo was born on Dec. 2, 2013 and Diara was born during the night between March 10 and 11, 2014. (Photo by Jens Meyer/AP Photo)

A rabbit sits in its cage in a gardener shop in Wiesbaden, central Germany, on April 19, 2014. Rabbits are one of the most popular pets in Germany. (Photo by Fredrik Von Erichsen/AFP Photo/DPA)

A four weeks old ring-tailed lemur (Lemur catta) plays in front of the mother in the Zoo in Erfurt, central Germany, Tuesday, April 22, 2014. (Photo by Jens Meyer/AP Photo)

An African Spoonbill catches fish at Kuimba Shiri bird park west of Harare, on April 25, 2014. Kuimba shiri is situated on the shores of Lake Chivero in a National Park boasting over 460 species of indigenous birds and is the only bird park in Zimbabwe. (Photo by Tsvangirayi Mukwazhi/Associated Press)

A Greater Adjutant Stork flies by a ragpicker looking for recyclable items at a garbage dump on Earth Day, on the outskirts of Gauhati, India, Tuesday, April 22, 2014. People across the globe hold events to celebrate the Earth's environment and spread awareness on how to conserve its natural resources on Earth Day, observed annually on April 22. (Photo by Anupam Nath/AP Photo)

Hugh Deegan clears the wall with Sun Prince during a demonstration of Falabella horses at Fairyhouse Racing, on April 20, 2014. (Photo by Morgan Treacy/Inpho Sports Photography Ireland)

An archer wearing ancient samurai warrior dress shoots an arrow to a target while riding on horseback during a Yabusame demonstration of samurai martial arts in the 13th century in Tokyo on April 19, 2014. Yabusame is a form of mounted archery in traditional Japanese archery with an archer on a running horse shooting three arrows at wooden targets. (Photo by Toshifumi Kitamura/AFP Photo)

Una, a Belgian Malinois, left, offers a kiss to Kat Smith, owner of the The Greatful Grind, after getting a treat during a coffee stop by Una's owner Ayn Sales in the Gateway area of Springfield, Ore., Wednesday, April 23, 2014. A morning routine, Una starts whining as soon as the car turns onto Gateway Boulevard, according to Sales. (Photo by Chris Pietsch/AP Photo/The Register-Guard)

27-year-old white polar bear Uslada shakes off water in her pool at the Leningrad Zoo in St. Petersburg, Russia, on April 25, 2014. (Photo by Alexander Demianchuk/Reuters)

A trained dolphin interacts with a girl during a dolphin therapy session in a dolphinarium in the Crimean resort town of Alushta, on April 24, 2014. (Photo by Yuriy Lashov/AFP Photo)

Dolphins lay at a pool nosing during a show rehearsal at a dolphinarium in the Crimean resort town of Alushta, on April 24, 2014. (Photo by Yuriy Lashov/AFP Photo)

Undated Swansea University handout photo of a sloth, as scientists have discovered that they are uniquely adapted to hanging around doing very little. The ponderous creatures, which spend 90% of their lives upside down, have internal organs fastened in place to prevent them squashing their lungs. (Photo by Becky Cliffe/PA Wire/Swansea University)

In this photo taken on April 11, 2014, and provided by the Wildlife Conservation Society , on April 24, 2014, “Tutti”, a female Western Lowland gorilla holds her baby at the Bronx Zoo Congo Gorilla Forest in New York. With the addition of two new baby gorillas recently born at the zoo, the Bronx Zoo's Congo Gorilla Forest is now home to 20 gorillas. (Photo by Julie Larsen Maher/AP Photo/WCS)

Jockey Samuel Cudjoe (1) runs his goat Bright Spark over the finish line to win the Class C2 Classic 100 metre race during the Carnbee/Mt Pleasant Community Council's 42nd annual sports meeting at the Mt Pleasant recreation ground, on Tobago island, April 21, 2014. The event is part of the island's annual Easter celebration. (Photo by Andrea De Silva/Reuters)

In this April 20, 2014 photo, an Arara parrot sits in an aviary at the city zoo in Rio de Janeiro, Brazil. Temperatures in Rio de Janeiro reached 30 degrees Celsius (86 degrees Fahrenheit). (Photo by Hassan Ammar/AP Photo)

Four Asian small-clawed otter pups, born in January, join their family to play, tumble and tussle at their public debut Thursday, April 24, 2014, at Woodland Park Zoo in Seattle, Wash. (Photo by Jordan Stead/AP Photo/Seattlepi.com)

A snapping turtle on display at the Shenandoah Valley Discovery Museum in Winchester, Va. awaits boxing for a move to its new home during “Moving Day” Wednesday, April 23, 2014. The museum will open in its new, larger location in Winchester, Va. on Saturday, May 10, 2014. (Photo by Jeff Taylor/AP Photo/The Winchester Star)

Undated handout photo issued by Scottish SPCA of a tawny owlet who attracted the attention of two cats after falling out of a tree and is now recovering in the Scottish SPCA's care,. Scotland's animal welfare charity was alerted on 17 April when a member of the public discovered the bird grounded in woodland close to Killermont View in Beardsen, Glasgow. The owl, estimated to be between five and six weeks old, is now in the care of the Scottish SPCA's National Wildlife Rescue Centre in Fishcross, Clackmannanshire. (Photo by Scottish SPCA/PA Wire)