CURRENT economic woes prompt memories of the cash-strapped 1940s and ’50s.
Things were tough in the decades after the war and people fled the county in their thousands. You were lucky to get work, ‘job-satisfaction’ was irrelevant and many spent their lives doing chores they hated.
Diasporas are normal in the bird world and avian square pegs in round holes are not unknown. In the most extreme cases species adopted bizarre lifestyles, even aping the behaviours of mammals and fish. Visiting the Southern Cape last August, I encountered two dramatic examples of avian career change. In one species, the bird’s ancestors tried to become fish. The other’s forebears sought to emulate horses.
Vasco da Gama, the first navigator to sail from Europe to India, saw African penguins near the Cape of Good Hope in 1497. The birds are also known as jackass penguins and, visiting a breeding colony, you soon discover why. A parent on duty at the nest will raise its bill skyward to produce a most convincing rendition of a donkey’s bray.
The jackass is one of 17 surviving penguin species. Although flightless, and totally helpless when on land, this bird group has been remarkably successful. Its origins go back 65 million years to the time when a great natural disaster wiped out most creatures on the planet, including the dinosaurs. What forces prompted the radical transformation which led to modern penguins we may never know, but ancient forebears adopted a lifestyle akin to that of fish. Their contour feathers shrunk to form a dense fur-like coat, the wings became fins and the powerful flight muscles were requisitioned as engines for this avian version of the torpedo.
Birds are the ultimate weight-watchers; carrying a few surplus ounces can make the difference between life and death when a predator strikes. Fish, however, must be as heavy as the water in which they swim, so penguins, to beat them at their own game, abandoned the lean-and-mean bird tradition.
The fat bullet-shaped bodies with their powerful flippers match, kilo for kilo, those of dolphins and seals. Penguins pioneered the plunge-diving life-style; the sea-mammals evolved it later.
Penguins are found only in the southern hemisphere. The Galapagos species breeds at the equator. It and the jackass, of sunny South Africa, like their creature comforts but some species prefer more austere conditions. The famous emperor penguin is a glutton for punishment. This, the largest member of the tribe, nests in the world’s coldest environment, the ice-plains of Antarctica, where no mammal, reptile or amphibian could survive, let alone breed. There are 35 colonies there and birds walk up to a 100km in the depths of the southern winter to reach them.
My other strange encounter at the Cape was with several ostriches. Like the penguins, their ancestors also dispensed with flying. Their wings are now too small to lift the world’s largest bird into the air. Being big is part the survival strategy of a creature which has disowned its avian heritage and aspires to be a sort of horse. With their huge eyes, ostriches and horses can see at night. The ostrich’s big head, most of which is taken up with the eye-balls, turns like a great radar antenna atop a giraffe-like neck. Hyper-vigilance is the name of the game.
As with the horse, long strong legs coupled with immense stamina keep the bird out of danger. Ostriches never bury their heads in the sand; they run. If cornered, their legs, with the avian equivalent of hoofs, can deliver a kick as lethal as that of a stallion.
Although the rheas of South America and the emus of Australia closely resemble ostriches, they are not relatives. All three evolved independently. Just why such bizarre transformations, and those of penguins, occurred mainly in the southern hemisphere is a mystery. The northern continents of Europe, Asia and North America account for most of the world’s land area; there is far less space down under. Did living in more restricted terrain, as European emigrants were often forced to do in centuries past, somehow goad their avian equivalents into becoming the most conspicuous turn-coats of the animal kingdom?
For more information on Table Mountain National Park, see www.tmnp.co.za
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