The researchers also hover low above the whales in a Cessna Skymaster 337 to survey and photograph the population. Each whale has a unique set of white patches on its skincallosity patternswhich serve as natural identification tags for each animal.
"We also photograph the backs of these animals, which are decorated with scars, most often from collisions with ships and struggles with fishing lines," said Brown. "Almost two-thirds of the population have scarring," she noted, adding that almost the entire population of right whales has been photographed.
Together, the techniques have given scientists "the best profile of any endangered species yet," said Brown. "We have combined at least 20 years of right whale observations with genetic profiles of at least 75 percent of the species to create one of the most detailed profiles of an entire species."
"We know these guys inside and out," she said.
Drawing a Family Tree
In some cases, Brown said, "we know stuff that even the whales don't know."
When mating, right whales gather in groups of two to fortya single female surrounded by as many as several dozen males. "So it is not surprising that the female probably has no idea which male fathered her calf," said Brown. Using DNA obtained from the skin samples, Brown and her colleagues can determine who the father is.
From DNA samples of 200 of the whales, the researchers found that all of those sampled were descended from only five females. Because the population is small and lacks genetic diversity, scientists are concerned that the species may be more vulnerable to threatening diseases.
Brown expects that over the next few years, the researchers will obtain a complete genealogy of the whalesa family tree that shows how all the 350 right whales are related to each other.
Yet there is still much to learn.
The good news is that there is roughly an equal number of males and females. The bad news, however, is that females produce a calf only every three years, or even longer.
"In 2001 we had a bumper crop of calves. We saw 30 in all," said Brown.
"But this is not a recovery," she added, explaining that the whales' birth rate is unpredictable. In 2000, only one calf was born. "We need the 2001 birth rate to continue for about ten years to feel like the population has some sort of buffer zone," said Brown.
An international consortium of researchers is committed to developing whale-watching technology and modifying fishing equipment that will reduce the number of injuries and deaths. "We'll know if we're successful if we see a reduction in the number of scars," said Brown.
As Brown completed this interview, she received a call from researchers in Canada. They had just sighted a whale without scarring on its back.
To learn more about a fisherman's efforts to create whale-friendly fishing gear, watch National Geographic Today, only on the National Geographic Channel, 7 p.m. ET/PT in the United States. Click here to request it.
SOURCES AND RELATED WEB SITES