Runners donned full black gorilla suits as they took to the streets of London to raise money for charity.
Around 500 fancy dress-clad participants took on The Great Gorilla Run, now in its thirteenth year, which sees entrants tackle a five-mile course around the capital.
Money raised from the event helps fund the Gorilla Organization's work in Uganda, Rwanda and the Democratic Republic of Congo.
It has so far generated £2.4 million for gorilla conservation projects.
Jillian Miller, Gorilla Organization executive director, said: "As always, it's a real joy to see so many people coming together for gorillas, putting their suits on, dressing up and having a great time running, walking and jumping through the streets of London.
"But we have to remember that there is a serious message beneath the fun."
She added: "Events like The Great Gorilla Run help provide valuable support for frontline ranger patrols within the gorilla habitat, while also funding projects aimed at addressing the long-term threats such as habitat loss and poaching."
