Participants hold red scarves as they celebrate the “Chupinazo” marking the start at noon sharp of the San Fermin Festival at Castle square in Pamplona, northern Spain on July 6, 2013. Ten of thousands of people packed Pamplona's streets for a drunken kick-off to Spain's best-known fiesta: the nine-day San Fermin bull-running festival. (Photo by Pedro Armestre/AFP Photo)

A fight between two female musk oxen, Norway, 2021. The image was captured in Norway’s Dovrefjell national park, where the musk ox (Ovibos moschatus) was reintroduced several years ago for its conservation. It is normal for males of this species to engage in fierce battles during the mating season but unusual for two females. (Photo by Miquel Angel Artús Illana)