Swimmers in fancy dress splash as they participate in the New Year's Day Loony Dook swim at South Queensferry, Scotland January 1, 2015. (Photo by Russell Cheyne/Reuters)

Two styles of cleaned bird's nest, Yan Zhan (L) and Su Zhan (R) await repacking at a processing plant in Kuala Lumpur, February 17, 2015. Prized in China for is alleged health benefits for hundreds of years, nests made from swiftlets' saliva are being mixed into coffee and cereal as the Southeast Asian producers of the delicacy seek to broaden its appeal, and their profit margins. The nests are among the world's most expensive foods, selling for up to $2,500 a kg and the swiftlets that weave them are indigenous to Indonesia, Malaysia, Thailand and Vietnam. (Photo by Olivia Harris/Reuters)

National Geographic photographer Steve Winter has spent most of his adult life shooting wild cats. Photo: A 14-month-old cub, cooling off in a pond, is riveted by a deer that appeared near the shore. Tigers are powerful swimmers; they can easily cross rivers four to five miles wide and have been known to swim distances of up to 18 miles. (Photo by Steve Winter/National Geographic)

A brushtail possum whose ears and legs have been burnt from recent bushfires sits in a cage before being transported to a wildlife hospital, in Batemans Bay, South of Sydney, Australia, 14 January 2020. (Photo by Steven Saphore/EPA/EFE)

A rickshaw man runs under the blooming cherry blossoms in Tokyo, Sunday, March 29, 2015. (Photo by Shizuo Kambayashi/AP Photo)

Undated handout issued by Take A View of Sunrise at Winnats Pass, Derbyshire, England which won the Visit Britian “You're invited” Award for the best image from an overseas entrant category in this year's Landscape Photographer of the Year Awards. (Photo by Sven Mueller/PA Wire)

Some dozens of long-finned pilot whales lay dead on a remote beach in Iceland after they were discovered by tourists sightseeing in the Snaefellsnes Peninsula in western Iceland aboard a helicopter, Thursday July 18, 2019. The whales were concentrated in one spot on the beach, many partially covered by sand. (Photo by David Schwarzhans via AP Photo)

A Thai veterinarian sterilizes a monkey in a bid to control the birth rate of the monkey population in Hua Hin city, Prachuap Khiri Khan Province, Thailand, 15 July 2017. (Photo by Narong Sangnak/EPA/EFE)