I think this was the first book by a naturalist that I ever read (and it was many years ago that I first read this book) that was utterly enchanting and engaging. Most books of this nature are didactic with occasional leaps into literary writing. Ackerman, in contrast, balances fact with fancy and reality with conjecture; she balances personal experience with the universal; she asks original questions that have no known answers; she merges conversation with conservation; she gives us a sense of who she is without losing the thread of what she's writing about. Not being particular scientific, I was surprised to find myself clinging to every word, reading the book straight through in perhaps two nights of bedtime reading.
The chapters on diverse topics can be read separately as individual essays, but there's a sense of progression of Ackerman's life that lends a personal touch to the book. These wonderful essays found their first home in The New Yorker. Subjects are all over the map: bats, alligators, penguins, and of course the whales of the title, which reads like a misprint - but isn't. In the process, Ackerman underscores man's responsibility to act in the protection of the world's other creatures: we are but one among many (and we're hugely outnumbered, BTW).
Besides being a perfect melding of animal lore, objective study, and conservation, The Moon by Whalelight is an example of nonfiction storytelling at its best.