For Spheniscus demersus is vanishing, and quickly. It's estimated that at the beginning of the 1800's, there were four million African penguins. By 1910, three quarters had vanished, with populations estimated at 1.5 million. It gets worse. 200,000 in the year 2000 had crashed to 55,000 only ten years later. Projections have this species reaching extinction by 2025. Hey. Wait a minute. That's ten years from now.
Why should this be so? Well, penguins lay an obligate clutch of only two eggs, and the chicks take a very long time to become independent, so their replacement rate is very low to start with. Incubation takes 40 days, and is done by both members of the pair. It can take as long as 130 days for a chick to become independent and fledge. All these natural history parameters aside, the big reason for the massive longterm, noncyclic penguin crash is us. Homo sapiens in all his wisdom has not figured out, or more correctly, hasn't figure out how to care, that when we overexploit species low on the food chain (in this case the small baitfish called pilchard), we cause earthquakes all the way up the chain, in those species that depend on smaller fish for their very existence. Not for fertilizer; not for fish emulsion, but for life itself. Overfishing caused a collapse of the commercial pilchard fishery in 1960, with disastrous results for penguin colonies. Chicks starved in the burrows (something we also see with our Atlantic puffins thanks to overfishing for capelin, their staple.) This is something we are also seeing in the North American red knot population since we decided that the highest use for horseshoe crabs, upon whose eggs the knots depend for food, was to be ground up for fertilizer. We hope that we've reversed that idiotic exploitation in time.
Finding no pilchard, African penguins were forced to switch to anchovies as their primary food, a fish which meets their basic needs, but is not ideal for rearing chicks, being lower in nutrients than the rich oily pilchard. So chick survival has declined, and chicks fledge thinner when fed on anchovies than on pilchard. The fledging period is highly variable, from 60 days to 130 days, depending on the quality of forage parents are able to find.
I'll briefly mention the massive oil spill on June 23, 2000, when the tanker MV Treasure sank between Robben and Dassen Islands, fouling the waters and 19,000 adult penguins at the height of the most successful breeding season on record. A massive rescue effort brought wildlife workers from all over the world to South Africa to wash, feed, and release the oiled birds, and (unbelievably) capture an additional 19,500 clean birds before the oil could reach their colonies. These birds were taken 800 km. east of Cape Town and released to swim back to their homes, giving workers time to clean the waters and shores before they got back in 1-3 weeks. An astounding 91% of the oiled birds survived, making this the largest animal rescue event in history, and a global effort at that.
The penguins would be in sorry enough straits without the constant threat of oil spills. We are witnessing an overall collapse of the penguin population, and as always, humans are the root cause of it. People are doing what they can to rescue oiled birds and encourage mainland breeding, protecting the colonies and offering shelters to nesting birds, but if we've taken their prey base out from under them, forcing the birds to swim longer distances for lower-quality fare, and negatively impacting chick survival pre-and-post-fledging, no amount of land-based management is going to correct the decline. Still, we try. We have to try.
I watched the penguins entering and returning from the sea. They're different birds in the water; it's the difference between seeing a seal galumphing clumsily on land and shooting like a torpedo through the water.
And on land, little gemmun in tuxedoes, I'm told; though I don't see people in the least when I look at penguins.
I see birds, probably the most miraculous birds of all, right up there with hummingbirds and swifts and ostriches for the bizarre array of their adaptations. Wingbones fused into paddles; blubber for insulation in frigid seas; barbule-free feathers that form a silky water-repellent sheath; a prodigious oil gland; feet way at the back of the boat like rudders, forcing an upright posture on land. What we see on land is not the whole story by a long shot.
It can take 12 to 22 months for a penguin to attain its adult plumage. This is done in a series of molts that take them from fuzzy brown natal down to the first juvenal plumage of steel-blue and white, and thence into the banded, pied tuxedo of adulthood. During the actual molt periods, which take about 20 days, the penguins are unable to enter the water, since their old feathers would become waterlogged and the new ones aren't waterproof yet. So they stay ashore and fast the entire time. And yes, they look about like we would if we were fasting for 20 days while our hair replaced itself. Which is to say:
The lone bird would stride by, on business.
Nothing takes you there like a video! Just sorry I can't bring you Smell-o-Vision, which is probably why Leon Marais got a unanimous "No, we're good!" when he asked if we'd like to visit Boulder's Beach's colony as well. Ha! We were ready for some less odiferous birds by then.