By Richard Black
Environment correspondent, BBC News website
A whale conservation success story, the recovery of the eastern Pacific gray whale, may not be quite what it seems.
Since the end of commercial whaling, numbers rose to about 20,000, thought to be the level they had been at before hunting began.
But a new study using genetic methods, reported in the journal PNAS, suggests pre-hunting numbers were much higher.
The scientists say climate change may be altering the whales' supply of food significantly.
Earlier this year, researchers noted signs that grays were showing distinct signs of malnutrition when they arrived at their winter breeding grounds along Mexico's Baja peninsula.
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more:
http://news.bbc.co.uk/2/hi/science/nature/6988339.stm