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Births aid right whales but survival seen as key

A baby boom has given a lift to the endangered North Atlantic right whale, which saw its annual calving season end last week with a near record number of births, according to researchers at the New England Aquarium.

Twenty-seven whales were born between the season's start in mid-December to its end on Thursday. That is second only to the 31 births recorded in 2001, the best year since scientists started tracking the births in the early 1990s.

The births are a piece of rare good news for a species that has lost five whales in the last six months, including at least two pregnant whales and another two females that were of breeding age. The latest death was reported early March in Virginia.

The whale was hunted nearly to extinction in the late 18th century and its worldwide population now numbers between 325 and 350. The juvenile whales have some significant obstacles before they can help the population rebound, said Lisa Conger, a senior biologist at the New England Aquarium who tracks the whale.

The whales are headed north for the summer from their calving grounds off the coast of Florida and southern Georgia to the Bay of Fundy in Canada. Along the way, they will run what Conger called a ''gantlet" of East Coast shipping traffic. Then the females have to live for 10 years before they can reproduce. The juvenile whales have a 25 percent mortality rate.

The female whales that have recently died are exactly the animals the species cannot afford to lose, Conger said. This year's high birth numbers help, ''but we're not overexcited," she said.

''In order for them to start giving back to the population, they have to survive," she said.

This year's numbers are a major improvement from just five years ago, when the right whale recorded a single birth. There were 16 births in 2004.

Kate Sardi, assistant director at the Whale Center of New England, said the improvement is probably because of a plentiful supply of plankton, the whales' primary food, rather than conservation efforts. Still, she said, the apparently abundant food supply is ''a very good sign."

Conger said 12 of the 27 new mothers also gave birth in 2002, putting them on an optimal cycle of three years between births.

But the problem of human-caused deaths remains a huge obstacle to any long-term gains for the whale, Sardi said.

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