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)

In this April 27, 2020 photo, a health worker helps another as she fainted because of exhaustion and long working hours during a swab test drive for COVID 19, in New Delhi, India. Two and a half months of nationwide lockdown kept numbers of infections relatively low in India. But with restrictions easing in recent weeks, cases have shot up, raising questions about whether authorities have done enough to avert catastrophe. Half of Delhi’s 8,200 hospital beds dedicated to COVID-19 patients are already full and officials are projecting more than half a million cases in the city alone by July 31. (Photo by Manish Swarup/AP Photo)

Ana Mendez Casteñeda smokes marijuana during “Fumaton 420” outside the national Senate in Mexico City, Tuesday, April 20, 2021. The demonstrators are calling for the legalization of marijuana. (Photo by Marco Ugarte/AP Photo)

The males, of the Oriental Garden species, are battling over territory in Solapur in the Maharashtra state, India on May 20, 2022. Occasionally, the tussle can be brutal, ending in a fatality with one lizard biting another to encourage them to retreat. (Photo by Ratnakar Hiremath/Solent News)

Suzanna Shahbazian of Canada competes in the Individual Exercises Final during Pan American Gymnastics Championships Rio de Janeiro 2022 at Carioca Arena 1 on July 09, 2022 in Rio de Janeiro, Brazil. (Photo by Buda Mendes/Getty Images)

A vendor wearing a protective face mask looks out of her store selling sugar-coated haws on a stick in Beijing, Sunday, April 12, 2020. (Photo by Andy Wong/AP Photo)

Visitors take masks off to take pictures as hydrangea flowers are fully blooming at Meigetsu-in Buddhist temple Friday, June 11, 2021, in Kamakura, south of Tokyo. (Photo by Kiichiro Sato/AP Photo)