You really need to watch this kangaroo street brawl – for science, of course

Whatever it is you're doing, no matter how important it is, take a moment to watch this video of brawling kangaroos. You won't be disappointed. 

Uploaded to YouTube last week by user Rodney Langham, the video shows a spirited brawl, set to Tchaikovsky’s "Waltz of the Flowers," between two adult male kangaroos in the middle of an otherwise quiet suburban street (there's no possible way to determine which country). For more than five minutes, the furry combatants punch, kick, and grapple, with no clear victor emerging at the end.

We don't know exactly what difference of opinion led to the marsupial melee, but it's not uncommon for male kangaroos of all species – these ones are probably eastern or western grey kangaroos – to resort to violence. Males will often fight to establish dominance, which buys them access to ovulating females as well as prime real estate on which to graze and rest.

Kangaroo fights are highly ritualized, with lots of posturing, grunting, and grass-pulling, but they are not just for show. A two-footed dropkick from a grey kangaroo – which can travel 20 feet in a single hop – can break bones and even bring death to an opponent. The person who shot this video was probably wise to keep his distance.

Unprovoked kangaroo attacks on humans are rare, but they still happen from time to time, particularly by kangaroos that have become accustomed to humans and their food. In the 19th and early 20th century it was common to train juvenile kangaroos to "box" human opponents with their forelimbs. The earliest known boxing film, shot in 1896,  depicts a match between a boy and a kangaroo. It's not clear who wins, but the marsupial appears to have the upper hand.