An African penguin is seen inside a breeding box at a national park in Simons Town, South Africa. Short of food and exposed to predators and the African sun, the penguins’ numbers are plummeting. But salvation may rest in a simple manmade solution — fiberglass housing that protects eggs and young chicks.

Boulders Beach, South Africa ? Nesting in the sparkling sand, preening on the rocks and darting through the waters, the penguins on the southern tip of Africa are the ultimate crowd-pleaser. But crisis looms.

Short of food, exposed to predators and the African sun, their numbers are plummeting. But salvation may rest in a simple manmade solution — housing for penguins.

Dotting the shore of this penguin colony near the Cape of Good Hope are 200 nesting boxes, each big enough to house a happy family of parents, eggs and chicks. The experiment has already worked well on a more distant penguin island in South African waters, and wildlife rangers are eagerly watching to see whether the boxes recently installed on Boulders Beach, where tourists can watch the birds up close, will prove equally attractive.

“You look at the penguins and think they have a lovely time in sunny South Africa, but it’s a struggle,” says Monique Ruthenberg, a ranger with the Table Mountain National Park in Cape Town, where summer temperatures recently hit 104 degrees.

Park authorities installed the boxes — made of a fiberglass mix, shaped like a burrow and dug into the sand to mimic the real nests — at Boulders Beach as part of desperate efforts to protect the dwindling populations of African penguins.

It has been a losing struggle. Numbers of the cute, curious creatures have plummeted from around 3 million in the 1930s to just 120,000 because of overfishing and pollution. Some experts fear the species will die out in as little as a decade, and are particularly alarmed at the prospect of global warming increasing the number of scorching days, raising water temperatures and altering fish migration patterns.

The Boulders Beach colony has fallen 30 percent from a peak of 3,900 birds in 2005 to 2,600 and some of the island colonies have suffered calamitous declines of 50 percent.

The African penguin, also called the jackass because of its bray, is the only one to inhabit the African continent. It has shorter feathers than the Antarctic birds because it doesn’t face such cold and is just 20 inches tall.

The Boulders Colony began in 1985 when a couple of penguins moved from a nearby island onto the beach in the naval base of Simon’s Town, decided they liked it and stayed. So many followed that authorities had to build fences to prevent them invading people’s gardens. But the tourists poured in.

About 600,000 a year now visit Boulders Beach, which boasts that it is the only place in the world where people can swim with penguins. The real life “Happy Feet” are unfazed by all the attention and, apart from a few who were killed while snoozing under visitors’ cars, don’t seem to have suffered from their contact with humans.

There is a constant risk from pollution. The last big oil spill was in 2000, when 20,000 penguins were trucked about 470 miles from Cape Town to Port Elizabeth to allow workers time to clean up oil from a wrecked tanker while the birds swam home.