Camera trapper Xavier Hubert-Brierre put this large mirror on the side of a road through the jungle in Gabon and left a camera there to record how the animals would respond to their own reflections. A silverback gorilla thought it was seeing another silverback and responded by trying to scare off the potential challenger… (Photo by Xavier Hubert-Brierre/Johns Hopkins University Press)

Crocodile skin is seen at a workshop in the old Medina of Marrakesh December 13, 2014. (Photo by Youssef Boudlal/Reuters)

Two hippopotamus are fed with pumpkins at the Hanoi Zoo, in Hanoi, Vietnam, 25 October 2018. The zoo has been the home for more than 800 animals of over 90 different species, including three hippopotamus, since it was built in 1976. (Photo by Luong Thai Linh/EPA/EFE)

A woman looks at head of bluefin tuna on display in front of a store at Tsukiji fish market in Tokyo, Monday, February 19, 2018. The large bluefin are particularly valuable in Japan, where they are considered a premium sushi and sashimi fish. A single fish sold for more than $1.75 million at an auction in Japan in 2013. (Photo by Koji Sasahara/AP Photo)

A brown bears cools off in a pool at the bear sanctuary near the village of Mramor, on August 18, 2020. The bear sanctuary was closed for visitors on August 18, as part of safety measures to curb the spread of the COVID-19 (novel coronavirus) disease. (Photo by Armend Nimani/AFP Photo)

A cow covered with foam scavenges in the waste left on the banks of the polluted Yamuna river in New Delhi on October 10, 2020. (Photo by Sajjad Hussain/AFP Photo)

People wearing protective face masks amid the coronavirus disease (COVID-19) outbreak are seen near foodstuffs, which are displayed for sale on a car in Omsk, Russia on December 4, 2020. (Photo by Alexey Malgavko/Reuters)

An Indian worker paints the hand of a huge clay model of a tribal woman on the Indian state of Karnataka's tableau for Republic Day parade, in New Delhi, India, Friday, January 22, 2016. Security has been tightened around the Indian capital as well as across the country ahead of Republic Day celebrations, held each year on Jan. 26. (Photo by Manish Swarup/AP Photo)