The coendou porcupine couple 'Joppi' (L) and 'Fletcher' nibble at a vegetables in their enclosure at the zoo in Frankfurt am Main, Germany, 03 December 2015. Coendou porcupines are nocturnal rodents related to porcupines and guinea pigs and native to the rain forests of Central and South America as well as Trinidad. (Photo by Arne Dedert/EPA)

A tufted puffin is seen in Kamchatka Territory, Russia on July 17, 2018. (Photo by Yuri Smityuk/TASS)

A palomino horse's mane is seen against the sky at Spancil Hill horse fair in Spancil Hill, Ireland June 23, 2018. (Photo by Clodagh Kilcoyne/Reuters)

A few revellers brave the cold and rain in Leeds, United Kingdom for the friday night out on December 30, 2022. Brits have kicked off their New Year’s Eve celebrations early with wild nights out up and down the country. (Photo by Nb press ltd)

Fast food got a whole new meaning in Hokkaido, Japan, where a vole was captured fleeing from a fox in the first decade of January 2025. (Photo by Hiroki Inoue/Solent News)

A Kazakh hunter walks with his tamed golden eagle during an annual hunting competition in Chengelsy Gorge, some 150 km (93 miles) east of Almaty February 22, 2013. (Photo by Shamil Zhumatov/Reuters)

A raccoon crawls out of its hiding place on the roof in Berlin, Germany on May 12, 2020. Every evening he leaves his sleeping place to go in search of food. (Photo by Britta Pedersen/dpa-Zentralbild/dpa)

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)