Mandarin ducks on the Solyonaya River in Vladivostok, Russia on April 19, 2019. Its world population around 25,000 pairs in total. Russian laws ban hunting mandarin ducks listed in the Red Book as an endangered species. (Photo by Yuri Smityuk/TASS)





Turtles warm themselves by sitting on a tree branch in a park in Bucharest, Romania, Monday, April 29, 2019. (Photo by Vadim Ghirda/AP Photo)





A brown hare (Lepus europaeus) in Oxfordshire, county in South East England on April 22, 2019. (Photo by Jerome Murray/Alamy Stock Photo)





One of three seal pups at the seal kindergarten which was put into service at Polarland recently in Harbin, China on May 1, 2019. All three are less than 3 months old and will play and grow together. (Photo by Xinhua News Agency/Barcroft Images)





A man takes a selfie next to a Maltese dog during the 2019 Shanghai World Dog Show in Shanghai on April 30, 2019 (Photo by Hector Retamal/AFP Photo)





Scaly-sided or Chinese mergansers (Mergus squamatus, male on left, female on right) in Yichun, Heilongjiang, China on April 24, 2019. (Photo by Costfoto/Barcroft Images)





A cuckoo in Thursley, Surrey, Tngland on April 27, 2019. The common cuckoo is a member of the cuckoo order of birds, Cuculiformes, which also includes roadrunners, anis and coucals. (Photo by Bebedi/Alamy Stock Photo)





Haflinger horses run during this years's first turn-out to grass at Europe's largest Haflinger stud-farm in Meura, Germany, Sunday, April 28, 2019. More than 300 Haflinger horses are living there. (Photo by Jens Meyer/AP Photo)





A flamingo rests his head in his feathers in his enclosure during a sunny day at the Hellabrunn zoo in Munich, Germany, May 2, 2019. (Photo by Michael Dalder/Reuters)





Falcons wait to receive medical attention at the Abu Dhabi Falcon Hospital in Abu Dhabi, United Arab Emirates April 28, 2019. (Photo by Christopher Pike/Reuters)





Giant male panda Xiao Liwu sleeps at the San Diego Zoo prior to his repatriation to China with his mother Bai Yun, bringing an end to a 23-year-long panda research program in San Diego, California, U.S., April 18, 2019. (Photo by Mike Blake/Reuters)





A visitor to the San Diego Zoo takes a selfie with giant male panda Xiao Liwu prior to Luwi's repatriation to China with his mother Bai Yun, bringing an end to a 23-year-long panda research program in San Diego, California, U.S., April 18, 2019. Picture taken April 18, 2019. (Photo by Mike Blake/Reuters)





Giant male panda Xiao Liwu eats a meal of bamboo at the San Diego Zoo prior to his repatriation to China with his mother Bai Yun, bringing an end to a 23-year-long panda research program in San Diego, California, U.S., April 18, 2019. Picture taken April 18, 2019. (Photo by Mike Blake/Reuters)





Giant male panda Xiao Liwu looks out from his home at the San Diego Zoo prior to being repatriated to China with his mother Bai Yun, bringing an end to a 23-year-long panda research program in San Diego, California, U.S., April 18, 2019. (Photo by Mike Blake/Reuters)





A boy who is experiencing the life of a Buddhist monk by staying in a temple for two weeks as a novice monk, feeds a bird as it sits on his hat at Everland amusement park in Yongin, South Korea, May 2, 2019. (Photo by Kim Hong-Ji/Reuters)





A peacock displays his plumage as part of a courtship ritual to attract a mate during a sunny day at the Hellabrunn zoo in Munich, Germany, May 2, 2019. (Photo by Michael Dalder/Reuters)





A duckling looks for food swimming in a lake in Bucharest, Romania, Monday, April 29, 2019. (Photo by Vadim Ghirda/AP Photo)





Two Egyptian goslings walk along the river Main in Frankfurt, Germany, Tuesday, April 30, 2019. (Photo by Michael Probst/AP Photo)





Charolais cows are pictured in a field on April 26, 2019 in La Jauniere near Chiché, Western France. (Photo by Guillaume Souvant/AFP Photo)





A tranquilized wild Indian elephant is lifted up with a crane as it is transported to the Amchang Wildlife Sanctuary after it wandered into a residential area in Sonapur, in Kamrup district in India's northeastern state of Assam on May 1, 2019. A wild bull elephant caused a major stir in an Indian city, wandering along the busy streets and crowds of photo-snapping onlookers before being tranquilised, officials said. (Photo by Anuwar Ali Hazarika/Barcroft Images)





Julie Witt, who helped raise former Kentucky Derby entrant Omaha Beach, rubs the horse's gums in the barn at Churchill Downs Thursday, May 2, 2019, in Louisville, Ky. The horse, which was the favorite in the race, was scratched because of a health issue. The 145th running of the Kentucky Derby is scheduled for Saturday, May 4. (Photo by Charlie Riedel/AP Photo)





A four-week old southern three-banded armadillo (Tolypeutes matacus) is rolled up into a ball next to its mother in the tropical house of Budapest Zoo in Budapest, Hungary on May 3, 2019. The South American insect-eating mammal and its close relative, the Brasilian three-banded armadillo (Tolypeutes tricinctus) are the only two species of armadillos capable of rolling into a complete ball to defend themselves when feeling threatened. (Photo by Attila Kovács/EPA/EFE)