Zoodsma and Thomas said the recent decline could be part of a normal cycle, or indicative of an environmental problem or other threat to the species. It could be that there were no other pregnant females out there. In the past, the whales were producing calves roughly every three years. A problem may exist in the food chain. Some researchers have noted that northern right whales have been skinnier and less robust than their southern counterparts, Thomas and Zoodsma said.
Calves require a lot of care and nourishment from their mothers if they are to survive.
They remain with their mothers for almost a year, Zoodsma said. She said the relatively warm winter could have kept the whales away. Right whales generally will not travel to water warmer than 68 degrees, researchers said. All rights reserved.