Since the females do show up every three or four years to give birth to a calf, the Southeast calving ground may be our only chance to get samples from these rarely seen females and their calves. Back at the lab, DNA is isolated from the skin samples using chemical detergents. By analyzing these fine white strands of genetic material, we can detect patterns specific to each individual whale and learn things that photos taken from a plane can't reveal. DNA allows us to determine the sex of an animal as well as its family history. Because males aren't present when the females give birth and play no known role in rearing calves, this is a difficult question to answer.
Mothers usually calve every three to five years.
Answering these questions can help us determine the size of the breeding population. This problem has been suspected in the Florida panther, which was reduced to a population of about thirty and displayed physical ailments associated with inbreeding. In that case, Texas cougars were introduced to offset the effects of inbreeding. That decision was controversial, and certainly no one's considering introducing southern right whales into our population. But even if inbreeding is not a factor, if there are only a few parents out there, it will take the population a long time to recover.