Behaviour: Mammals category. Giant Gathering by Tony Wu, USA. Dozens of sperm whales mingled noisily off Sri Lanka’s northeast coast, stacked as far down as Tony could see. This was a congregation of dozens of social units, like a gathering of the clans. Aggregations like this could be a critical part of the whales’ rich social lives but are rarely reported. Some two thirds of the population was wiped out before commercial whaling was banned in 1986. This kind of major gathering could be “a sign that populations are recovering”, says Tony. (Photo by Tony Wu/Wildlife Photographer of the Year 2017)

A young Bengal tiger cub smuggled into the US and seized at the Mexico border is displayed for the media during Operation Jungle Book at the US Fish and Wildlife Service in Torrance, California on October 20, 2017. Operation Jungle Book, a law enforcement initiative led by the US Fish and Wildlife Service that targeted wildlife smuggling, resulting in federal criminal charges against defendants who allegedly participated in the illegal importation and/ or transportation of numerous animal species – including a tiger, monitor lizards, cobras, Asian “lucky” fish, exotic songbirds and several coral species. (Photo by Mark Ralston/AFP Photo)

A counter-protester grabs the flag of a pro-police demonstrator during a rally, following weeks of protests against racial inequality in the aftermath of the death in Minneapolis police custody of George Floyd, in Boston, Massachusetts, U.S. June 27, 2020. (Photo by Brian Snyder/Reuters)

Racegoers try to shelter from the rain during day one of the Cazoo Derby Festival at Epsom Racecourse in Surrey, United Kingdom on Friday, June 4, 2021. (Photo by John Walton/PA Images via Getty Images)

Members of the Chinese military orchestra march past a screen showing the Chinese Communist flag on Tiananmen Square before a celebration marking the 100th founding anniversary of the Chinese Communist Party, in Beijing, China, 01 July 2021. China celebrates on 01 July the 100th anniversary of the founding of the ruling Chinese Communist Party. (Photo by Roman Pilipey/EPA/EFE)

People wade through a road flooded by heavy rain in Kurume, Fukuoka prefecture, western Japan, Saturday, August 14, 2021. Torrential rain pounding southwestern Japan triggered a mudslide early Friday that swallowed some people and was threatening to cause flooding and more landslides in the region. (Photo by Kyodo News via AP Photo)

A participant in the Downtown Parade kicks off the Houston Livestock Show and Rodeo in Houston, Texas, US on February 25, 2023. (Photo by Reginald Mathalone/NurPhoto/Rex Features/Shutterstock)

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)