A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

Cows belonging to Samburu tribesmen walk around the carcass of an elephant killed by armed cattle herders in Mugui Conservancy, Kenya February 11, 2017. Kenya has declared the ongoing drought affecting many parts of the country a national disaster, calling for aid to counter the situation which is posing a major risk to people, livestock and wildlife. (Photo by Goran Tomasevic/Reuters)

A Thai veterinarian takes a picture of a 2-year-old orangutan during a health examination at Kao Pratubchang Conservation Centre in Ratchaburi, Thailand, August 27, 2015. Thai veterinarians from the Department of National Park Wildlife, and Plant Conservation conducted a health check of 14 orangutans for preparation for the repatriation to their country of origin, Indonesia. (Photo by Athit Perawongmetha/Reuters)

A Chinese tourist wears protective gloves as she holds a baby Siberian tiger as they pose for pictures at the Heilongjiang Siberian Tiger Park on August 16, 2017 in Harbin, northern China. The center is one of two Siberian tiger parks in the Chinese province of Heilongjiang, about 500 kilometers (300 miles) from the border with Russia. It is considered the world's largest for breeding the Siberian, or Amur, tiger which is listed as endangered by the World Wildlife Federation. (Photo by Kevin Frayer/Getty Images)

A hyena eyes a herd of zebra at Lake Nakuru National Park, Kenya, August 19, 2015. The Park is home to some of the world's most majestic wildlife including lions, rhinos, zebras and flamingos. The scenery is stunning, from forests of acacia trees to animals congregating at the shores to drink. UNESCO says that with rapid population growth nearby, the area is under "considerable threat from surrounding pressures," particularly deforestation, a contributing factor in floods. (Photo by Joe Penney/Reuters)

Nepalese Mahuts with their elephant participate in elephant picnic as a part of the12th Chitawan Elephant Festival at Sauhara, Chitawan, some 154 kilometer from the capital of Kathmandu, Nepal, 28 December 2015. More than 80 elephant with their Mahuts joined the elephant picnic. The five-day festival began on 26 December to spread awareness about wildlife and promote tourism. (Photo by Hemanta Shrestha/EPA)

Opposites can attract and Anzac a doe-eyed baby kangaroo has become best friends with Peggy, a tiny squint-eyed wombat. Their unlikely union developed after the pair - both orphans - shared a pouch at the Wildlife Kilmore Rescue Centre in Victoria, Australia. At just over five months old, Anzac was brought to the centre after being rescued in the Macedon Ranges. The joey is in the mother kangaroo's pouch for about eight months, depending on the species, but Anzac was abandoned a few months before he was ready to be free.