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)

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)

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)

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)

Contestant Nathalie De Oliveira of Brazil prepares backstage before the final show of the Miss International Queen 2016 transgender/transsexual beauty pageant in Pattaya, Thailand, March 10, 2017. Thai contestant Jiratchaya Sirimongkolnawin was crowned Miss International Queen 2016. The 2016 show was postponed from November last year due to Thailand's mourning period of its late King Bhumibol Adulyadej who died at age 88 on October 13, 2016. (Photo by Athit Perawongmetha/Reuters)

Transgender Kendra Ferrari, 21, performs during Miss Night Queen beauty contest in Guatemala City, Friday, June 15, 2012. Ferrari won the pageant and will represent the transgender community for one year. (Photo by Rodrigo Abd/AP Photo)

Miss USA 2012 Nana Meriwether crowns Miss Connecticut USA Erin Brady the new Miss USA during the 2013 Miss USA pageant at PH Live at Planet Hollywood Resort & Casino on June 16, 2013 in Las Vegas, Nevada. (Photo by Ethan Miller)