The Ark Files - Head to head

Heads are extremely useful weapons of war. From battling beetles to rampaging rhinos, a good set of headgear can win or lose the day.

Horns and antlers

These are the most common head adornments. Both are used for head-to-head combat but they have very different structures.

Horns are not branched. They are also permanent skull fixtures, made up of a bony core covered with keratin (the material in fingernails and hooves). True horns are only found on antelope, cattle, sheep and goats (and their relatives).

Antlers are branched. They are also shed each year and made only of bone when they are fully grown. When they are forming they are covered with soft velvet. Antlers are only found on deer.

Levers and forceps

The Hercules Beetle, the Rhinoceros Beetle and, most impressive of all, the 13-centimetre-long Goliath Beetle are a few of the insects that develop horns from outgrowths of their external body skeleton. These are not all the same shape. Some emerge from the head and curve backwards, some grow from the back of the neck and point forward, and some species have a pair of horns which meet caliper-like above their heads.

Beetles don't charge or push when they fight. Instead they use their horns as levers or forceps to knock each other over and hurl one another sideways. The horns of the Stag Beetle are not really horns at all but rather greatly lengthened mandibles (modified mouth parts) that point forward like tusks. Rival Stag Beetles conduct wrestling matches high up in tree branches. Eventually one will get a good hold on the other and heave it upwards until it is forced to let go its footholds on the bark. Then it is hurled unceremoniously to the ground.

Antler agro

The Alaskan Moose is the giant of the deer family and can measure just over two metres high at the shoulders. Its antlers begin as small bumps on the head during the breeding season in spring and when their growth is complete three months later, they can have a spread of two metres - the biggest of any living animal. The wide, middle section of each antler acts as a shield to block attacks. Edging the antlers are numerous, sharp spikes which are used to cut and stab and can do serious injury.

The antlers clash and interlock as males contend for females. These majestic beasts push each other back and forth until one of them tires or is stabbed and gives up. Contests go on for about a month and then the antlers fall off, only to be regrown for the next breeding season. There is a tale of the discovery of two moose skeletons found with their antlers hopelessly entangled... they must have starved to death.

Rubbing noses

Rhinoceroses have horns, too, but they are different from those on cattle and sheep. They do not have a bony core but are formed from a solid mass of compressed hairs (keratin). Rhinos' horns grow continually at a rate of eight centimetres a year and can regrow if broken off.

Males fight a lot during the mating season. Bull rhinos will charge with very little provocation and can reach speeds of 48 km/h over short distances. When charging males meet they use their horns to gouge and their bulk to push.

Rhinos are extensively hunted for their horns which are prized for their supposed properties as aphrodisiacs and medicines and used as status symbols in the form of carved dagger handles. The horns of a rhino are both their glory and their downfall.

Nerves and heads of steel

Cattle and sheep head butt one another to settle their
disputes.

The magnificent ridged horns of Ibex sweep back from their heads like scimitars. These animals hold their butting contests on dizzying rocky outcrops high in the Alps where surefootedness and unshakeable nerves are essential.

In springtime the Rocky Mountains echo with the collisions of America's Bighorn Sheep. Aptly named, the rams have extremely strong horns that spiral on each side of their reinforced foreheads. The rams definitely need their thick horns and heads because they charge towards each other at full speed, meeting head-on.

Antelope are more gentlemanly in combat. Their long, curved horns are used to lock and grapple with one another rather than being used as battering rams.

Shall we dance?

A completely different and rather unlikely head ornament is found on the Australian Antler Fly. Male flies have long, paddle-like growths on either side of their heads and, when a similarly matched pair meet, they use their ‘antlers’ to push
at each other.

This to-ing and fro-ing gets very energetic and results in them rearing straight up on their middle and hind legs, each trying desperately to topple the other. This curious dance only ends when one of them loses its balance. When it recovers, it concedes defeat and flies away.