Tall tails

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What’s the point of a tail, you might wonder? After all, we humans seem to manage perfectly well without one. But this extra appendage does a vital job for most animals, from propulsion (crocodile) and counterbalance (cheetah) to seduction (widowbird) and signposting (warthog). In fact, a brief glance at some of Africa’s more notable exponents of tail power might just leave you wondering what you’re missing. By Mike Unwin.

widowshutterstock_382075369Male widowbirds of the Euplectes genus, such as the long-tailed widow (Euplectes progne), develop outrageously long tail feathers in the breeding season. These extravagant plumes form a jet black train, which the bird flaunts by cruising low over its grassland territory in a slow, flapping display flight. The object is to attract a mate – and research using artificially lengthened plumes has demonstrated that females do indeed go for males with the longest tails. There is, inevitably, a trade-off: the males’ tails make them both very conspicuous to predators and very slow to escape. Small wonder, then, that they shed their finery as soon as the breeding season is over.

The short, tufted flywhisk of a spotted hyena may not be nature’s most impressive tail, but it is fundamental to the animal’s complex lexicon of body language. Hyenas have a strictly hierarchical society and they deploy their tail – along with their ears, mane, voice and posture – to convey both rank and mood. A dominant individual will hold its tail high, often curling forward over its back; a subordinate one will lower its hindquarters and curl its tail below its belly. When approaching an individual of unknown rank the tail flicks hesitantly, inviting clarification. This social semaphore extends to dealing with other species: hyenas driving a lion off its kill do so with tails held high.

The fierce Kalahari sun sends most creatures heading for the shade. But not the cape ground squirrel. This enterprising rodent creates its own shade by holding its long tail forward over its body like a furry parasol. Thus protected, it continues its vigorous quest for roots and seeds in temperatures that would fry the brains of many other creatures. The tail also supports the squirrel while it stands upright to scan for danger. And if that danger materialises in the form of a deadly snake, the squirrel flourishes its tail like a matador’s cape, provoking the reptile into futile strikes until it gives up and slithers away.

Linger long by an African river and you might just hear the sound of applause. But the apparent volley of clapping echoing across the water may well be coming from the rear end of a hippo. These massive amphibious mammals use their stubby little tails to engage in dung-scattering wars at their territorial boundaries. The rules of engagement are simple: one male stands up in the water, stares out his adversary and then – backing into position – lets fly, switching his tail back and forth to shower the dung over his rival. The noise alone sends a strong message to rivals further afield. A hippo also uses this same technique to demarcate its territory on land.

No matter how impressive your tail, there are times when it must make the ultimate sacrifice. Many smaller lizards, such as this speckled day gecko (Phelsuma guttata) will shed their tail when caught by a predator. The still-wriggling member diverts the pursuer, allowing the lizard to dash for safety. To enhance this defence tactic, some species have a tail brighter than the rest of their body, making it a more visible target. Most tail-shedders do so by contracting the muscles in front of weak spots in their tail vertebrae – a trick known as intravertebral autonomy. The tails can regenerate. The new appendage consists of tough cartilage, rather than bone, and a joint or change in colour usually marks the spot where the old one broke off.

 

Originally published in Travel Africa edition 52, Autumn 2010

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