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)

An exhausted Rohingya refugee woman touches the shore after crossing the Bangladesh-Myanmar border by boat through the Bay of Bengal, in Shah Porir Dwip, Bangladesh, September 11, 2017. (Photo by Danish Siddiqui/Reuters)

The Aurora Borealis (Northern Lights) lights up the sky near the village of Pallas (Muonio region) of Lapland, Finland September 8, 2017. (Photo by Alexander Kuznetsov/Reuters/All About Lapland)

Mave Grace, 11, who had part of her arm chopped off by militiamen when they attacked the village of Tchee, stands with her sister Racahele-Ngabausi, aged two, in an Internally Displaced Camp in Bunia, Ituri province, eastern Democratic Republic of Congo, April 12, 2018. (Photo by Goran Tomasevic/Reuters)

Raquel Poti performs on stilts during the Amigos da Onca street Carnival party, in Rio de Janeiro, Brazil, Saturday, February 10, 2024. (Photo by Bruna Prado/AP Photo)

Silvia Zecchin (4L) wearing a crown poses with a group of Maries, at the end of the ceremony that crowned her Maria of Carnival 2024, in Venice, Italy, 13 February 2024. The young student of Political Science at the University of Padua, in addition to teaching rhythmic gymnastics to children, was elected at the end of the Gala Dinner hosted in the Apollinee rooms of the Teatro La Fenice in Venice and hosted by Maurice Agosti and Alice Bars. (Photo by Andrea Merola/EPA)

Hundreds of Marilyn Monroe impersonators wearing blonde wigs take part in the Marilyn Jetty Swim in coastal suburb of Brighton Adelaide to raise money for cancer charity in Adelaide, SA Australia on February 4, 2024. (Photo by Amer Ghazzal/Alamy Live News)

Participants wearing colorful costumes take part in the Flowers Parade of the 151th annual Carnival of Nice, in Nice, France, 20 March 2024. The annual Carnival of Nice run from 17 February to 03 March 2024, and the main theme will be “King of Pop Culture”. (Photo by Sebastien Nogier/EPA)