More animal fun from the St. Louis Zoo. These two half-brother Western lowland gorillas, Nadaya and Bakari, like to play and laugh together (the vocalizations you hear is laughter). Other gorillas at the zoo get shy when they're being watched, but these too don't seem to care as they playfully antagonize each other.
This play "fighting" is a very common way for them to play and is much different than an actual gorilla fight. You can see Nadaya's large canine teeth that he could definitely do damage with if he wanted to. This playing is just a way for these boys to maintain their close bond and show that they trust each other. Our bachelor group has four males and these brothers will usually back each other up if there are ever issues with the older two males.