There is a three-year calving interval for right whales. They are pregnant for a year, nurse for a year, then need a year to rest. However, scientists have detected that the calving interval has increased, on average, to a little more than four years. We're seeing more animals, that are waiting four, six or seven years. Why, we haven't been able to answer yet.
Food is always a theory.
The future of the species is hanging in the balance at present, says Brown. On the other hand, if the present rate of increase of 2.5 percent annually can he maintained, the population of 300 would double in 35 years. If the rate of increase could somehow be increased to 7 per cent, the population would double in 15 years. It's going to take a long time. Even 500 animals would make me feel a whole lot better.