Lions at the Blair Drummond safari park, Stirling, UK explore left over Christmas trees decorated with meat and spices by their keepers on December 30, 2016. (Photo by Andrew Milligan/PA Wire)





Keepers at the city zoo are celebrating after the birth of a rare Rothschild’s giraffe calf, seen left with its mother in Chester, UK on December 29, 2016. (Photo by Steve Rawlins/Chester Zoo)





A giant panda eats bamboo in Xiuning Panda Park in Huangshan City, east China's Anhui Province, December 28, 2016. (Photo by Shi Guangde/Xinhua/Barcroft Images)





A baby Bornean orangutan called Sabah is pictured at Madrid zoo on December 27, 2016 in Madrid, Spain. (Photo by Pacific Press/Rex Features/Shutterstock)





A female mantled guereza holds its four-day-old baby in the Nyiregyhaza Animal Park in Nyiregyhaza, 245 kms east of Budapest, Hungary, Wednesday, December 28, 2016. (Photo by Attila Balazs/MTI via AP Photo)





In this photo taken on December 12, 2016, a cat streches on a counter top in a Chinese and western medicine shop in Hong Kong. Four-legged “assistants” can be found perched in certain shops across Hong Kong, keeping a nonchalant eye on business while the city does its non-stop bustle past their storefronts. (Photo by Anthony Wallace/AFP Photo)





Dwarf mongooses pictured in their enclosure in the Hagenbeck Animal Park in Hamburg, Germany, Thursday December 29, 2016. (Photo by Axel Heimken/DPA via AP Photo)





In this Thursday, December 8, 2016, photo Susan Frank pets one of her mulefoot pigs at Dogpatch Farm in Washington, Maine. The American mulefoot hog was once the rarest of all U.S. livestock breeds, and they’re still listed as critically rare by the Livestock Conservancy. Frank accounts for about a dozen of the pigs. (Photo by Robert F. Bukaty/AP Photo)





A black kite takes flight near the city of Beer Sheva, southern Israel December 26, 2016. (Photo by Baz Ratner/Reuters)





Sea gulls stand on a roof in Hyde Park in London, Britain December 28, 2016. (Photo by Stefan Wermuth/Reuters)





Giant panda Yang Yang and her twin cubs, Fu Feng and Fu Ban, which were born on August 7, are seen in their enclosure at Schoenbrunn Zoo in Vienna, Austria, in this handout photo released December 30, 2016. (Photo by Daniel Zupanc/Reuters/Schoenbrunn Zoo)





Giant panda twin cubs Fu Feng and Fu Ban, which were born on August 7, are seen in their enclosure at Schoenbrunn Zoo in Vienna, Austria, in this handout photo released December 30, 2016. (Photo by Daniel Zupanc/Reuters/Schoenbrunn Zoo)





Giant panda twin cubs Fu Feng and Fu Ban, which were born on August 7, are seen in their enclosure at Schoenbrunn Zoo in Vienna, Austria, in this handout photo released December 30, 2016. (Photo by Daniel Zupanc/Reuters/Schoenbrunn Zoo)





Fourteen year-old male sea lion “Leo” attends a calligraphy training session to paint the character for “Rooster” at the Hakkeijima Sea Paradise aquarium in Yokohama, suburban Tokyo on December 26, 2016. The event marks the upcoming Lunar “Year of the Rooster” and is part of the aquarium's New Year's attractions until January 31. (Photo by Kazuhiro Nogi/AFP Photo)





Sea gulls fly at the beach of the Baltic Sea in Timmendorfer Strand, Germany, Tuesday, December 27, 2016. (Photo by Michael Probst/AP Photo)





In this Thursday, December 8, 2016, three-day-old mulefoot piglets nuzzle their mother at Dogpatch Farm in Washington, Maine. The American mulefoot hog was once the rarest of all U.S. livestock breeds, and they’re still listed as critically rare by the Livestock Conservancy. There are fewer than 500 registered, purebred, breeding mulefoots. (Photo by Robert F. Bukaty/AP Photo)





A white-spectacled bulbul flies over a tree near the west bank city of Nablus City, West Bank on December 28, 2016. These species live around fruit plantations, gardens, and cities. (Photo by Alaa Badarneh/EPA)





Fern, the toucan that flew out of Courtney Chapman's back yard aviary in Fullerton, Calif., in May, sits in a cage at Omar's Exotic Birds in Brea, Calif., Thursday morning, December 29, 2016. On Tuesday, Fern flew into a Yorba Linda auto repair shop, where an Omar’s Exotic Birds employee, Connor Chubbuck, captured her. On Thursday, she was reunited with her owner. (Photo by Mark Rightmire/The Orange County Register via AP Photo)





Fern, the toucan that flew out of Courtney Chapman's back yard aviary in Fullerton, Calif., in May, sits in a cage at Omar's Exotic Birds in Brea, Calif., Thursday morning, December 29, 2016. (Photo by Mark Rightmire/The Orange County Register via AP Photo)





A picture taken on December 07, 2016 shows Gray Cranes flocking at the Agamon Hula Lake in the Hula valley in northern Israel. More than half a billion birds of some 400 different species pass through the Jordan Valley to Africa and go back to Europe during the year. Some 42,500 Gray Cranes stayed this winter in the Agamon Hula Lake instead of migrating to Africa, taking advantage of the safety of this artificial water source. Local farmers feed the birds with corn in a bid to prevent them from destroying their agricultural fields. (Photo by Jack Guez/AFP Photo)





A titmouse picks a tree-hanging red apple on December 28, 2016 in the north-eastern part of Bergen, Germany. (Photo by Frank Rumpenhorst/DPA)





An adorable forest vole perches on a snowball to nibble the carrot nose of a miniature snowman, joined by another vole which clambered onto the snowman's head as temperatures plunged to minus 15 degrees Celsius in Voronezh, Russia on December 23, 2016. (Photo by Vadim Trunov/Solent News/Rex Shutterstock via ZUMA Press)





A ring-tailed lemur sunbakes at Melbourne Zoo in Melbourne, Victoria, Australia on December 21 2016. (Photo by Julian Smith/EPA)