A cat stretches on top of dried seafood in a shop in the Sheung Wan district of Hong Kong on August 7, 2020. International Cat Day, celebrated on August 8, is a day to raise awareness for cats and learn about ways to help and protect them. (Photo by Isaac Lawrence/AFP Photo)

A man carries a sack of corn through the Comayaguela market on the outskirts of Tegucigalpa, days after general eletions in Honduras, Tuesday, November 30, 2021. Free Party presidential candidate Xiomara Castro, the wife of ousted former president Manuel Zelaya, has taken a commanding lead in Honduras' elections, capping a 12-year effort. (Photo by Moises Castillo/AP Photo)

Thousands of bright Red Potatoes are washed and sorted at a vegetable market. Workers hose down tons of the vegetables before packing them into sacks at the market in Shibganj Upazila, Bogura, Bangladesh on February 19, 2023. The Red La Soda spuds are then taken to the country's capital Dhaka. (Photo by Mustasinur Rahman Alvi/Rex Features/Shutterstock)

A vender arranges goods for sale at a market on the outskirts of Buenos Aires, Argentina, Wednesday, January 10, 2024. (Photo by Natacha Pisarenko/AP Photo)

A pigeon stretches its wings in the Ka Faroshi bird market in Kabul on July 16, 2022. (Photo by Lillian Suwanrumpha/AFP Photo)

A potential bidder carefully examines pieces of Tuna in order to ascertain the quality and to estimate its price ahead of the Tuna auction at the Tsukiji fish market on February 28, 2012 in Tokyo, Japan. (Photo by Daniel Berehulak /Getty Images)

A zebra walks through the recently flooded Safari Park located at Safari World November 2, 2011 in Bangkok, Thailand. (Photo by Paula Bronstein /Getty Images)

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)