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)

Medical students play with coloured powder as they participate in Holi celebrations, the Hindu spring festival of colours, inside Moti Lal Nehru Medical College campus in Allahabad on March 16, 2022. (Photo by Sanjay Kanojia/AFP Photo)

Commended. In late May, about a quarter of a million snow geese arrive from North America to nest on Wrangel Island, in northeastern Russia. They form the world's largest breeding colony of snow geese. Photographer Sergey Gorshkov spent two months on the remote island photographing the unfolding dramas. Arctic foxes take advantage of the abundance of eggs, caching surplus eggs for leaner times. But a goose (here the gander) is easily a match for a fox, which must rely on speed and guile to steal eggs. “The battles were fairly equal”, notes Sergey, “and I only saw a fox succeed in grabbing an egg on a couple of occasions, despite many attempts”. Surprisingly, “the geese lacked any sense of community spirit”, he adds, “and never reacted when a fox harassed a neighboring pair nesting close by”. (Photo by Sergey Gorshkov/Veolia Environnement Wildlife Photographer)

An Afghan vendor selling birds to be kept as pets wait for customers in his shop in Kabul on December 11, 2021. (Photo by Ahmad Sahel Arman/AFP Photo)

In this Friday, February 1, 2019, photo, Filipino-Chinese display piggy banks at the start of celebrations leading to next week's Lunar New Year in Chinatown, Manila, Philippines. This year is the Year of the Earth Pig on the Lunar calendar and is supposed to represent abundance, diligence and generosity. (Photo by Bullit Marquez/AP Photo)

An officer wipes sweat off the face of a Chinese People's Liberation Army (PLA) honor guard soldier as they rehearse for a welcoming ceremony for New Zealand's Governor-General Sir Jerry Mateparae at the Great Hall of the People in Beijing, Tuesday, July 21, 2015. (Photo by Mark Schiefelbein/AP Photo)

Nutrias venture near the camera at the river Nidda in Frankfurt am Main, Germany, 15 June 2017. The rabbit sized animals are often confused with biebers by amateurs. (Photo by Boris Roessler/DPA)

A nurse holds a painting of Prime Minister Boris Johnson clapping with blood on his hands as part of a demonstration of NHS workers at hospitals across London to demand a 15 per cent pay rise by the government in London, Wednesday, August 26, 2020.(Photo by Kirsty Wigglesworth/AP Photo)