A young male fiddler crab is dwarfed by an older male of the same species, looming behind it at Morua estuary, in the Gulf of California, Mexico on January 4, 2022. Whereas female fiddler crabs have small claws of equal sizes, the males’ pincers can vary in size, with the small one used to pick up food and the larger to impress females. (Photo by Claudio Contreras/Solent News)

Combat between two male stag beetles, Italy, 2022. During the mating season, male stag beetles (Lucanus cervus) go into a frenzy, with lively but harmless clashes, in which bigger males often have the advantage over smaller ones due to their impressive mandibles. Longer larval development and genetic traits can increase the size of some individuals, but all saproxylic beetles are threatened by poor forest management, logging and dead wood removal to “clean” the forest. (Photo by Iacopo Nerozzi)

Women Wrestlers, Bolivia. Lucha libre (Bolivian wrestling) is one of the most popular sports in the country. Women wrestlers are known as cholitas and have in the last ten years become popular in the sport. Here, Carmen Rosa and Yulia la Pacena perform in a benefit show to raise money for the bathrooms of a school in La Paz, Bolivia, 26 June 2011. (Photo by Daniele Tamagni)

The Enemy, 1944. With the outbreak of world war two, photojournalism was enlisted in defence of Mother Russia. In this photo by Anatoli Egorov, who was wounded in action, corporal Stepan Vasiljevich Ovcharenko shoots at enemy troops with a machine gun. (Photo by Anatoli Egorov/Lumiere Brothers Center for Photography)

A man takes a photo of a mural entitled “Thank goodness Silvia is here” (Meno male che Silvia c'è), representing former Italian prime minister and presidential candidate Silvio Berlusconi dressed as a woman, by Italian street artist Salvatore Benintende aka TvBoy, on January 21, 2022 in Milan. (Photo by Piero Cruciatti/AFP Photo)

“This grey adult male seal enjoys a good grin while lying on the beach”. (Photo by Michael Hutch/SplashdownDirect via Rex USA)

A volunteer approaches a male toad to pick him up from a road near Berlin on March 18, 2012 in Gueterfelde, Germany. (Photo by Sean Gallup/Getty Images)

A model parades an outfit by Australian label Micky In The Van at Melbourne Fashion Week in Melbourne on November 18, 2021. As Australian labels were paraded on the runway at Melbourne Fashion Week, protests took place outside by female warehouse workers claiming they are earning up to $10 less an hour than male counterparts. (Photo by William West/AFP Photo)