Wild Blue: A Natural History of the World's Largest Animal
by Dan Bortolotti
Thomas Dunne Books, 2008
Wild Blue is simply a great book in every way. It introduces us to a mammal we know surprisingly little about, despite said mammal's status as the largest creature ever to live on Earth. The author is outstanding at explaining cetacean biology, scientific principles, technology, and so on without ever losing his sense of wonder. He also introduces us to the key figures in blue whale research and lets us know what motivates them.
Bortolotti tackles the always-present question: how big do they get? While 33m and up has been claimed, he reports that about 30m is the longest validated measurement, with the largest whales approaching 182 metric tons. He also looks into taxonomy (the once-controversial pygmy blue whale has largely been accepted as a subspecies, but there's plenty of debate about how many subspecies there are, what populations live where (and whether they intermix), etc.
Wild Blue is scientifically exacting yet always accessible to the nonspecialist reader like myself. That's a very difficult tightrope for any author to walk, and Bortolotti never loses his balance. This will stand for a long time as the definitive work on its subject.