Whales Return to Frolic Off South Africa : Periled species: Residents of coastal resort are protective of animals staging a comeback from near extinction.

The whales in the bay outside this small South African resort sometimes keep townspeople awake at night with the noise they make.

Southern right whales, once almost wiped out by hunters, can be heard making groaning sounds in the bay about 75 miles southeast of Cape Town.

“They sound like cows mooing, but in a cave--so loud that the sound wave hits you,” said boatyard owner Johan Brink.

Hermanus residents are proud of the whales, which return annually to calve and frolic in the bay.

The 40-ton animal, which grows to more than 45 feet, is so placid, fat and predictable that whalers once found it easy prey--thus the name right whale.

In just one South African bay during the late 18th Century, whalers caught 1,200 southern right whales in two years.

By 1830 numbers had collapsed, but hunting continued until 1940, when South Africa enforced a League of Nations ban.

The Northern Hemisphere’s right whales are almost all gone.

According to researcher Peter Best, when the slaughter stopped, there may have been only 20 or 30 adult females frequenting South African waters, suggesting a total population of 100. This compares with more than 12,000 calving females before the whalers came.

Now there are about 300 adult females among an estimated 1,000 right whales frequenting South Africa. They are the most important single group in a total population of 3,000 or 4,000 frequenting Southern Hemisphere coastlines, also including Tristan da Cunha and Australia.

“The population is now increasing by about 7% a year,” Best, a member of the Pretoria University’s Mammal Research Institute, said in an interview in Cape Town.

Little is known about the right whales. They may live for 50 year, but it is hard to tell because there are so few old whales.

One long-term danger may come from inbreeding. All the whales now living descended from a few survivors, and this genetic bottleneck could cause unhealthy traits to be widely spread.

Apart from a few who are killed by collisions with boats or washed up in fishing line, the southern right whales off South Africa seem fairly secure for now.

From June to November they return from their feeding grounds near Antarctica, where they feast off tons of tiny crustaceans, to loll off the South African coast.

Tourists and staff run out of a seafront restaurant to watch in awe as an exuberant cow leaps up and arches sideways repeatedly, throwing up fountains of water, while her newborn one-ton baby floats quietly nearby.

The whales come 100 yards offshore, so close that the characteristic patterns of rough white skin on their heads, which distinguish each individual, are clearly visible.

To watch a right whale roll upside down in the swell, waving its squarish flippers like a Roman Emperor summoning a slave, is to understand relaxation.

“To hear a whale blow is like hearing the breath of life,” said local conservationist Nan Rice.

Some of the world’s toughest laws against disturbing whales are in force here, largely due to Rice’s campaigning.

No boat can be closer than 300 yards from a surfaced whale and must leave at once if one approaches.

Rice has built up a Dolphin Action and Protection Group with thousands of supporters who keep watch on the whales.

“In the 1930s, people sometimes used to say, ‘Oh, we saw Wendy the Whale today.’ But I never did,” she recalled.

“By the time we got ‘round to protecting them, they were nearly extinct.”