We've all been there - someone bigger and tougher takes something we want and there's nothing left to do but cry about it. This is the louder, fluffier version of that, filmed earlier this month by YouTuber Alicia Alexander in Adelaide Hills, South Australia. While koalas are generally pretty quiet animals - they sleep for 18 to 22 hours a day - during the breeding months between August and February, territorial skirmishes often break out between the males, accompanied by the relentless grunts, screams, and bellows you hear in the video above.

During koala breeding season, the dominant males will patrol their territory, going from tree to tree to check if any females are ready to mate. This tree monopoly often sees young males that have just reached sexual maturity - from 18 months old - pushed out of the mating game until they're old and tough enough to fight back.

While it's not clear exactly how old the pair of fighting koalas are in the video above, the unsuccessful one is definitely younger, which would explain why all it can do is sit at the base of the Eucalyptus and make its dissatisfaction known. 

While it's likely he will be bullied out of access to females until he's about four or five years old, Alicia Alexander mentions in the video description that he did eventually gain access to that tree when the older male wasn't looking. "The little koala won as it had claimed the the tree by nightfall," she says.

At around the 0:29 mark, you get to hear another type of koala vocalistion from the dominant male - a deep, grunting bellow, the purpose of which is to attract nearby females. Amazingly, researchers have discovered that these bellows have a pitch about 20 times lower than they should be, considering the koala's size. According to Mary Bates at National Geographic, "it's actually more typical of an elephant-sized animal".

Back in 2013, researchers in the UK reported that these bellows - recordings of which were used to create T. rex roars in Jurassic Park - are produced by an organ found in no other animal on Earth. A team from the University of Sussex identified unique vocal cords inside koalas that are completely separate from their larynx (or voice box). "It's the first evidence in a land-dwelling mammal of an organ other than the larynx that is devoted to producing sound," Bates explains.

And now in case you're feeling down about the momentarily treeless koala above, here's another video from Alicia Alexander of a beautiful young koala that's not yet learnt to be wary of humans. Even for those of us living in Australia, to see these magnificent and entirely unique animals up so close is really special.