Khan, a five-year-old male White Bengal tiger, looks on inside an open-air cage at the Royev Ruchey zoo in Krasnoyarsk, Russia, October 21, 2016. (Photo by Ilya Naymushin/Reuters)
A man looks at the description of a sculpture depicting 17-year-old male chimpanzee Jaska, by Gillie and Mark, in London, Tuesday, September 20, 2022. (Photo by Vadim Ghirda/AP Photo)
A woman in a wedding gown walks to a mass wedding ceremony, held 17 male inmates, in the Carcel Villa Hermosa prison in Cali, Colombia, August 19, 2016. (Photo by Jaime Saldarriaga/Reuters)
Two Red Deer stags stand in the early morning mist in Richmond Park on October 15, 2011 in London, England. Autumn sees the start of the “Rutting” season where the large Red Deer stags can be heard roaring and barking in an attempt to attract females known as bucks. The larger males can also be seen clashing antlers with rival males. (Photo by Dan Kitwood/Getty Images)
A photographer in Somerset, South West England captured the mating rituals of toads as several males attempt to mate with one female all at once. (Photo by John Waters/NPL)
Buyan, a male Siberian brown bear, cools down under a stream of water sprayed by an employee in an enclosure on a hot summer day, at the Royev Ruchey zoo in Krasnoyarsk, Russia on June 14, 2019. (Photo by Ilya Naymushin/Reuters)
An Oriental Garden Lizard sits on a tree in Gauhati, India, Tuesday, April 16, 2019. During the breeding season, the male lizard's head and throat turn a bright color. (Photo by Anupam Nath/AP Photo)