These incredible pictures capture the moment a young gorilla challenges a silverback for dominance at a zoo – by slugging it out in a brutal brawl.
In one corner – weighing in at more than 400lbs – is Chip, a 14-year-old dominant silverback who rules the roost.
But he was on the receiving end of a barrage of punches from 12-year-old Pende – the wannabe looking to take his crown at Detroit Zoo in America.
Visitors watched in amazement as the pair bared their teeth, traded punches and kicks and wrestled in an awesome show of power.
Pende was the surprise winner, leaving his older half-brother sulking in the corner nursing his bruised ego.
Their keepers expect to see a number of similar clashes between the pair as Pende challenges for supremacy over the coming years.
Photographer Kellyanne Berg, who captured the moment, said: ”I go to the zoo quite often and have only seen them really go at it like this once.
”My heart was pounding so fast that I was surprised my hands weren’t shaking – it was truly spectacular to watch.”
Detroit Zoo has three gorillas with Chipua born in September 1996, Pendeka in January 1998 and Kongo-Mbeli in December 1998.
Sparring among males of this age is not uncommon as they are in transition to silverback gorillas.
Detroit Zoo’s Patricia Mills Janeway said: ”Chip is older and has always been the dominant male but Pende and Kongo are in transition so we’re at a time when we will see a change in the relationship among all three males.
”I wouldn’t be surprised if there is a shift in the dominance rank in the near future. The younger males will challenge Chip to see how they size up against him.
”It won’t be uncommon to see some robust sparring over the next couple of years as they hash it out.”
The gorilla is the largest of the primates with Africa their natural habitat. In captivity the magnificent beasts can live into their forties and weigh up to 650lbs.
Chip sulks as Pende celebrates his shock victory