Aurora, an eight-year-old female polar bear, swims in a pool which was recently filled with water after the winter season, at the Royev Ruchey zoo in the suburb of Krasnoyarsk, Russia April 16, 2018. (Photo by Ilya Naymushin/Reuters)





A photo taken on April 19, 2018 shows one of the famous peacocks of the United Nations Offices in Geneva making its way The peacocks are living in the 46- hectare Ariana Park surrounding the UN Offices and roaming freely on its grounds. (Photo by Fabrice Coffrini/AFP Photo)





One of the famous peacocks of the United Nations Offices in Geneva flies down from a bicycle shed on April 19, 2018. (Photo by Fabrice Coffrini/AFP Photo)





A newly- hatched baby Olive Ridley turtles makes its way to the sea as an adult turtle looks on in Ganjam district in eastern India' s Odisha state on April 19, 2018. Millions of baby Olive Ridley turtles are hatching and entering the Bay of Bengal Sea on the coast of Odisha state in eastern India over the last few days. (Photo by Asit Kumar/AFP Photo)





A Syrian brown bear cub plays with its mother “Martine” in its enclosure at the zoo of Servion, Switzerland, 17 April 2018, Three Syrian brown bear cubs were born at the zoo on 19 January 2018. (Photo by Cyril Zingaro/EPA/EFE)





Baby grey geese grazing under the watchful eyes of their parents on the banks of the river Main, Frankfurt am Main, Germany on April 16, 2018. (Photo by Frank Rumpenhorst/DPA)





A zookeeper feeds 31-day-old baby of Javan green magpie by a glove puppet imitating a parent, at the Zoo in Prague, Czech Republic, 17 April 2018. The Javan green magpie (Cissa thalassina) is one of the world's most endangered bird. (Photo by Martin Divisek/EPA/EFE)





Pink flamingos frolic in their enclosure at the Madrid zoo in Madrid, Spain, April 18, 2018. (Photo by Paul Hanna/Reuters)





The undated photo provided by Zoologische Gaerten Berlin on Wednesday, April 18, 2018 shows giraffe Max with a research device strapped to his head. The Berlin zoo said Wednesday that handlers trained giraffe Max for 10 months until they got him used to wearing the transmitter on his head, which makes him look a bit like a jogger wearing a headlamp for an evening run. (Photo by Zoologische Gärten Berlin via AP Photo)





A Sphynx cat stares sitting on its owner's lap during an international feline beauty competition in Bucharest, Romania, Saturday, April 14, 2018. More than 250 cats take part in the two-day competition in the Romanian capital. (Photo by Vadim Ghirda/AP Photo)





An orca whale hunts sea lion pups on a beach at Punta Norte, Valdes Peninsula, Argentina, Tuesday, April 17, 2018. The orcas' predatory ritual occurs annually in the Southern Atlantic coast in March and April, coinciding with the development of the sea lions when the young cubs are learning to swim. (Photo by Daniel Feldman/AP Photo)





An orca whale hunts sea lion pups on a beach at Punta Norte, Valdes Peninsula, Argentina on Tuesday, April 17, 2018. (Photo by Daniel Feldman/AP Photo)





The gorilla “Fatou” eats a birthday cake at the Berlin Zoo, Germany, April 13, 2018. (Photo by Axel Schmidt/Reuters)





Flamingos interact in their enclosure during a sunny day at Munich's Hellabrunn Zoo, Germany April 13, 2018. (Photo by Michael Dalder/Reuters)





Capercaillies are seen at the mating ground in a forest near the village of Vyganashchy, Belarus April 14, 2018. Picture taken April 14, 2018. (Photo by Vasily Fedosenko/Reuters)





Four excited pooches wait anxiously in a car at the Montgomery County Animal Services and Adoption Center in Gaithersburg, Md. on April 15, 2018, as their owner signed them up for free rabies vaccinations. The clinic vaccinated more than 200 cats and dogs during the two-hour event. (Photo by Michael S. Williamson/The Washington Post)





A lionfish is seen at the Table Top dive site off the coast of Capo Greko on January 15, 2018. After colonising parts of the Atlantic on the east coast of the United States and the Caribbean, lionfish are now invading the Mediterranean. The outbreak in the Mediterranean has scientists, fishermen and divers so worried that they have launched a campaign to reduce its numbers. (Photo by Emily Irving-Swift/AFP Photo)





A swan sits in its nest in a lake near Queen Louise' s Bridge in central Copenhagen, Denmark, on April 17, 2018. The swan' s nest is partly made out of trash from the lake and contains several eggs. (Photo by Mads Claus Rasmussen/Reuters/Scanpix Denmark)