Profitable Wonders James Le Fanu
Each of the 10,000 species of birds is exceptional in its own way, though some apparently are more exceptional than others.
The ‘Top Fifty’ of the ‘evolutionary most distinctive’, according to Professor Walter Jetz of Yale University, writing in the journal Current Biology, includes the ostrich, the world’s fastest animal on two legs, with a cruising speed of thirty mph.
Then there is the heaviest – and only flightless – parrot, the New Zealand Kakapo, that gets by, breeding only once every three years. The female selects her partner from a fashion parade of potential suitors.
From Venezuela comes the monogamous, nocturnal, cave-dwelling oilbird that must, like the bat, rely on echolocation to find its food in the dark. Its stores of rich body fat are highly prized as cooking oil (thus the name).
The flamingo must be the most distinctive of all. Though its instantly recognisable long, slender neck, spindly legs and pinkish-red plumage are so familiar, its many physical and behavioural peculiarities are readily overlooked.
Those peculiarities are inseparable from, and determined by, its habitat. This is among the harshest on earth for the East African lesser flamingo. It lives in the shallow, evaporated, intensely salty lakes of the Rift Valley, whose ‘viscous, slimy and unbelievably foul’
water brims with the blue-green algae on which it feeds.
Hence the long, spindly legs on which the flamingo wades through the soft mud. And, being so high off the ground, hence too the necessity for that long, slender neck that sweeps down, head flexed, on to the surface of the water.
Thus the flamingo feeds ‘upside-down’ – a peculiarity indeed, that entails a complete reversal of standard beak anatomy: the upper bill, rather than being fixed and capacious, is shallow and mobile, articulating upwards on to a fixed and capacious (rather than shallow and mobile) lower bill.
‘The flamingo’s flip-flop is complete and comprehensive – in form and motion,’ notes naturalist Stephen J Gould. ‘The shapes are overturned, the sizes reversed, the slotting inverted, the buttressing transposed.’
And the flamingo’s mode of feeding, too, is ‘surpassingly rare, unique amongst birds’, comparable only to the filtering mechanisms of the giant baleen whale. The piston-like motion of its muscular tongue, pumping to and fro twenty times per second, sucks twenty gallons a day of that ‘slimy and unbelievably foul’ water into its mouth through a fine mesh of hair-lined teeth that exclude all but the minuscule algae that constitute its diet.
Those algae, too, are the source of that distinctive pink-red colouration – rich in carotenoid chemicals metabolised first in the flamingo’s liver, then concentrated in the oily preening gland near its tail.
Spanish biologist Juan Amat describes observing how the flamingo, besides smoothing and tidying its feathers, rubs its cheek against this gland, transferring the pigment on to its neck and breast.
Protected within its harsh habit from the attention of predators, the lesser flamingo flourishes, aggregating in tens and hundreds of thousands to create the most astonishing spectacle in the ornithological world.
Apart from the colour of the scene and the awe-inspiring vitality of its seething, bustling life, the observer is struck by its incessant clamour. When not resting or feeding, they divert themselves with a range of bizarre, ritualised displays – the ‘head-flag’ and ‘wing-salute’, the ‘twistpreen’, ‘hooking’ and ‘marching’.
‘They pack into a tight mass, standing very upright, the breast of one practically resting on the back of the bird in front,’ writes flamingo enthusiast Malcolm Ogilvie. ‘Then they set off at a fast run, abruptly reversing direction every so often. The overall effect is to produce a darker pink mass of ‘marching’ birds, moving to and fro within the general flock. All that can be seen from a distance is a forest of twinkling red legs and madly twitching heads, above a solid wall of pink bodies.’
And how peculiar is that?
What’s for dinner? Rift Valley slime