Workers attempt to bring a tranquillised black rhino to the ground before dehorning in an effort to deter the poaching of one of the world's endangered species, at a farm outside Klerksdorp, in the north west province, South Africa, February 24, 2016. (Photo by Siphiwe Sibeko/Reuters)

People look at sharks from an underwater room structure installed in the Aquarium of Paris, France, March 14, 2016. Airbnb and the Aquarium of Paris offer contest winners a night underwater sleeping with sharks and create a research platform for “misunderstood” shark species. (Photo by Charles Platiau/Reuters)

A Common Blue Morpho butterfly lands on the arm of Garbiella as it and hundreds of other butterflies from around the world fill the bird aviary for the next month at the San Diego Zoo Safari Park in San Diego, California March 13, 2015. Called the Butterfly Jungle, the exhibit has over 30 species of butterflies. (Photo by Mike Blake/Reuters)

A Hawaiian cleaner wrasse provides its cleaning services to a yellowfin goatfish in a reef community off the Big Island in Hawaii. Cleaner species help rid their hosts of ectoparasites, dead tissue, bacteria and fungi. Studies have shown cleaning to play a vital role in keeping many reef ecosystems healthy. (Photo by Marty Snyderman/Caters News Agency)

A veterinarian from the zoo of Besancon feeds “Soa”, a female crowned sifaka, in Besancon, eastern France, on February 18, 2019. The crowned sifaka is a critically endangered species from Madagascar. There were only 6 females over 20 individuals living in 7 zoos worldwide end of 2018. (Photo by Sébastien Bozon/AFP Photo)

“Warming up”. This photo I capture in the early afternoon, the animal species of lemurs fly. Photo location: Sambas, West Kalimantan, Indonesia. (Photo and caption by Hendy Mp/National Geographic Photo Contest)

Zookeepers measure the length of a pueblan milk snake in the Reptile House of ZSL London Zoo as part of their annual weighing and measuring of their animals on August 25, 2011 in London, England. The heights and weights of over 750 different animal species at the zoo are recorded into the International Species Information System, to monitor their health and share the data with other zoos across the world. (Photo by Oli Scarff/Getty Images)

“Pilot whales are cetaceans belonging to the genus Globicephala. There are two extant species, the long-finned pilot whale (G. melas) and the short-finned pilot whale (G. macrorhynchus). The two are not readily distinguished at sea and analysis of the skulls is the best way to tell the difference between the two species. Between the two species, pilot whales range in waters nearly worldwide with long-finned pilot whales living in cooler waters and short-finned pilot whales living in warmer waters. Pilot whales are among the largest of the oceanic dolphins, exceeded in size only by the killer whale. They and other large members of the dolphin family are also known as blackfish”. – Wikipedia

Photo: Pilot whales swim in Loch Carron on May 20, 2011 in South Uist, Scotland. A major operation is underway to prevent up to 100 pilot whales from stranding on the rocky shoreline of Loch Carron on South Uist in the Western Isles. (Photo by Jeff J Mitchell/Getty Images)