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 participant Saint Nicholas parade walks from house to house dressed in the traditional devil and Nicholas costumes in Francova Lhota district of Zlin, Czech Republic on December 3, 2017. This type of parade is one of the most popular age old tradition in a few villages in Wallachia region (eastern part of Czech Republic). Saint Nicholas walks the streets going from house to house three days and Saint Nicholas gives sweets to children and the devils get up to mischief. (Photo by Lukas Kabon/Anadolu Agency/Getty Images)

Filipino children play as they are doing caroling activities on the street near an airport, days before Christmas in Manila, Philippines, 20 December 2017. Filipinos celebrate the longest Christmas in the world which starts as early as September every year. (Photo by Francis R. Malasig/EPA/EFE)

A train attendant wearing a protective face mask stands on a train to Wuhan, at the railway station in Beijing, China, 29 March 2020. Wuhan, the epicenter of the coronavirus outbreak, partly lifted the lockdown allowing people to enter the city after more than two months. Chinese authorities eased the quarantine measures as cases of Covid-19 across China have plummeted, according to Chinese government figures. (Photo by Roman Pilipey/EPA/EFE)

A woman in a face mask dances inside the club on the opening of the summer season for “Villa delle Rose”, one of the most famous clubs on the Adriatic Coast on June 20, 2020 in Rimini, Italy. The Villa delle Rose is among the first dance clubs to reopen in the Adriatic Riviera after the Covid-19 pandemic. (Photo by Max Cavallari/Getty Images)

Police officers in action during the eviction of the “Liebig 34” squat, at Friedrichshain district in Berlin, Germany, 09 October 2020. A local court ruled in favor of the eviction of the self-declared “anarcha-queer feminist” house project at Liebig street 34 in June 2020. The house project is considered a stronghold of the left-wing scene in the German capital. (Photo by Filip Singer/EPA/EFE)

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)

Performers in costume wait to take part in the carnival on the main Parade day of the Notting Hill Carnival in west London on August 29, 2022. London's Notting Hill carnival celebrates Caribbean culture, at a carnival considered the largest street demonstration in Europe. (Photo by Susannah Ireland/AFP Photo)