National Geographic : 1973 Mar
Oil and Penguins Dont Mix Photographs by MIKE HOLMES ON SEASIDE STROLLS he looks like a proper old gentleman, elegantly suited and full of stuffed-shirt decorum. But the jackass penguin gives the game away when he opens his beak. Loud and strident, his cry is an inelegant bray -a startling "hee-haw." Thus the bird got the most familiar of his nicknames. Today his cry seems more like a call for help, as problems-largely caused by man-claim an increasing toll of these birds. Thirty years ago millions of jackass penguins nested on coastal islands off South Africa's tip. One primary breeding ground, tiny Dassen Island, lies 32 miles northwest of Cape Town. Today scarcely 60,000 birds return to Dassen each spring and autumn on their twice-yearly nesting cycle, after weeks of fishing in offshore waters. Where nest-robbing seabirds once posed the only real threat to the island's penguin colony, human egg collectors have diminished the birthrate and guano harvesters have destroyed many nests. Fishing fleets net the pilchard and anchovy on which the penguins feed. Ironically, the teeming schools of such fish depend, at least in part, on the penguins, whose nitrate-rich guano deposited in the sea nourishes plankton eaten by the fish. But the most devastating hazard is oil pollution. Since the closing of the Suez Canal in 1967, rerouted oil tankers-some 650 each month grind past Dassen. Oil from shipwrecks and from bilges pumped at sea has killed penguins by the tens of thousands. Jackass penguin (Spheniscus demersus), also called black footed, African, Cape penguin. Distinctive characteristics: adult stands 15 inches high; 6-7 pounds; white stripe on each side of head. Seeking their lifetime mates, birds put on a show of hee-hawing and flipper flapping, as above. Proclaiming an engage ment, a pair nuzzles. The nest site they choose may serve throughout their lives. The female lays two to three eggs; chicks hatch in five to six weeks, with both parents alternately tending the young. Breeding range: Coastal islets of South and South-West Africa. Total population: 100,000 to 250,000. Ten-year life-span. First described by members of Vasco da Gama's expedition of 1497.