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)

Bride Katty Malang Mikunug with friends, takes a photo before the wedding on October 21, 2017 in Saguiaran in Lanao del Sur, southern Philippines. Paulo Mamayo Ambor, 22, a resident of Marawi who got displaced by the fighting between government troops and IS-inspired militants, weds Katty Malang Mikunug, 22, a resident of an adjacent town in Saguiaran. Philippines President Rodrigo Duterte declared Marawi liberated, following the death of Abu Sayyaf leader Isnilon Hapilon and one of the Maute brothers, Omar Maute, after nearly five months of fierce urban battle inside the besieged city. The fighting started May 23, and left more than 1,000 people dead, whilst displacing at least 400,000 people. (Photo by Jes Aznar/Getty Images)

People pose for photos in the snow in the Manhattan borough of New York City, New York, U.S., December 2, 2019. (Photo by Carlo Allegri/Reuters)

Clowns pose for a picture during the International Clown Day in Guadalajara, Mexico, on December 10, 2019. (Photo by Ulises Ruiz/AFP Photo)

A man tries to extinguish an advertisement board set on fire during a demonstration of French labour union members and workers, as France faces its 38th consecutive day of strike against French government's pensions reform plans, in Paris, France on January 11, 2020. (Photo by Gonzalo Fuentes/Reuters)

Self-titled Pricasso – real name Tim Patch, 71, – is using his very own pen*s to create his masterpiece – and claims to have made close to £500k from his saucy paintings. Here: Pricasso gets to work with his tools - and paints The Sun's newspaper correspondent Amy Nickell with his bits in London, England on November 5, 2019. (Photo by Stewart Williams/The Sun)

A brushtail possum whose ears and legs have been burnt from recent bushfires sits in a cage before being transported to a wildlife hospital, in Batemans Bay, South of Sydney, Australia, 14 January 2020. (Photo by Steven Saphore/EPA/EFE)

Migrant children run away from clashes with Mexican National Guards after their group crossed the Suchiate River on foot from Guatemala to Mexico, on the riverbank near Ciudad Hidalgo, Mexico, Monday, January 20, 2020. More than a thousand Central American migrants hoping to reach the United States marooned in Guatemala are walking en masse across a river leading to Mexico in an attempt to convince authorities there to allow them passage through the country. (Photo by Santiago Billy/AP Photo)