photo: NOAA After being hunted out of the northern Pacific waters off Canada and Alaska in the mid 1960s, Blue Whales began reappearing there in the late 1990s. But now, for the first time, there’s photographic evidence that some of these whales are migrating up from California, rediscovering migratory routes

thought forgotten. At the same time, Blue Whale populations off California have been declining. New Scientist sums up the speculation as to why this might be happening:…

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Blue Whales Rediscover Lost Migration Routes: Here are Four Reasons Why This Might be Happening