Why Do Kangaroos Box? Fighting Males Explained

Why do male kangaroos fight?

In kangaroo mobs, males do not defend territories. Instead, they compete for females that are ready to mate. A female red kangaroo can breed at almost any time of year, so males follow and guard females as they come into season, and rival males challenge each other.

Fights establish a dominance hierarchy. The biggest, strongest males usually win and do most of the mating. Smaller or younger males learn to back off, and a beaten male often avoids the winner afterward. As a dominant male ages or loses condition, younger rivals eventually overthrow him.

This is the same basic pattern as in many other mammals with strong male competition. The red deer rut in Europe, for example, also uses displays and fights to decide which males breed.

Sparring vs serious fights

Not all boxing is serious. Biologists separate two kinds:

Sparring is a form of play-fighting. It lets young males practice, test their strength against others and learn where they stand without much risk. Older males may spar with younger ones, and a contest may stop and start several times.

Serious fights are rarer, faster and more dangerous. They usually happen near a female in season, when the prize is greatest. Most contests are settled quickly, often as soon as one male realizes he is outmatched. A beaten male usually turns away or hops off, and the winner rarely chases him far. Because both animals risk injury, kangaroos rely heavily on displays and sparring to avoid full fights whenever possible.

How do kangaroos box?

A fight usually starts with display. Males stand tall on their toes and tail to look as big as possible, scratch their chest or the ground, pull at grass and stare at the rival. If neither backs down, they move closer.

The two then stand upright, face to face. They grab at each other’s head, neck and shoulders, lock forearms and try to push the opponent off balance. They may jab, scratch and claw at the face. Compared with gray kangaroos, red kangaroo males tend to do more wrestling.

If the fight escalates, a male leans back on his thick tail, which takes his weight, and kicks forward with both hind feet at the rival’s belly. The hind legs are extremely powerful, and the long claw on the fourth toe can cut skin. Big males are thought to have especially thick skin on the belly for protection, yet serious fights can still leave wounds.

Why do male kangaroos have such big arms?

Adult male red kangaroos develop much larger shoulders, chest and forearms than females, and these keep growing as males age. This difference is thought to have evolved through male competition: males with stronger arms grip, push and wrestle better, win more fights and father more young.

Size matters too. Males can weigh twice as much as females or more, as explained in how big is a red kangaroo? In a mob, the heaviest male is usually the dominant one.

Do kangaroos box with people?

Kangaroos generally avoid people. Problems occur mainly when kangaroos have become used to humans, especially where they are fed by hand. A large male may then treat a person as a rival and stand tall, grab or kick. Serious injuries are uncommon and deaths extremely rare, but a big male’s kick can cause deep cuts.

The safest approach is simple: watch from a distance, never feed kangaroos, keep dogs under control and do not approach a male that stands tall facing you. If someone is injured, seek emergency medical help immediately (000 in Australia, 911 in the US, 112 in the EU or 999 in the UK).

Kangaroo boxing in culture

The upright fighting stance looks so much like a human boxer that kangaroos became a popular image in the late 19th and early 20th centuries, when “boxing kangaroo” acts appeared in circuses and shows. Those performances are now seen as cruel and no longer take place in most countries.

Today the boxing kangaroo survives as a cheerful national symbol. A green-and-gold boxing kangaroo flag became famous in Australia after the country won the America’s Cup sailing race in 1983, and it is still waved at sporting events.

For more about how kangaroos live, breed and survive in the outback, see the red kangaroo profile.