This lengthy tome (nearly 700 large-sized paperback pages), subtitled “Island Biogeography in an Age of Extinction,” was recommended by Joe Morlan, who taught an Introduction to Field Ornithology class I took earlier this year, as the best science/nature book he’s ever read, and, although I am not extremely well-read in that genre, I must agree!
Quammen weaves several tales into this epic of non-fiction. One is the history of the field of island biogeography, starting with Darwin & Wallace and leading through the present time, another is a survey of extinction and near-extinction, and a third is a personal narrative of Quammen’s travels to the sites of important events in the first two threads.
His writing is wry, humorous, and sometimes critical. He takes pains not to bog down in jargon or mathematics, and he apologizes for his introduction of a formula describing the species-area concept, inviting us to immediately forget it.
The crux of the book is the concept of ecosystem decay, whereby a patchwork of isolated habitat is much less biologically healthy and diverse than a single connected area comprising the same area. He travels to the Amazon to witness first-hand an experiment in setting aside various sizes of rainforest in the middle of clear-cut operations. Below a certain size (which of course varies depending on the ecosystem in question and its inhabitants), everything starts to unravel, typically starting with the loss of the top-of-food-chain predators and working its way down. He also observed the decay at the edges of these amazonian reserves, with trees starting to die, the understory drying out, and the whole thing shrinking slowly, but inevitably.
Particularly interesting to me were the sections on modern biogeographical theory as it relates to nature preserve design, and the efforts of current leaders in the field to capture the notion of ecosystem decay and minimum sustainable populations in a generalizable form.
Although the notion of island biogeography may seem restricted, as much of the world’s land mass is continental, the concept applies to much more than just oceanic islands. A tall mountain rising out of a desert, for example, can be considered an island, because there is no similar habitat nearby, and an uncrossable obstacle (desert) for many animals. As alluded to above, a nature preserve, set aside in a developed area, also functions as an island for the same reasons, ditto man-made lakes and reservoirs as they pertain to fish populations.
Despite taking me several months to read, every page was a pleasure, and I enjoyed savoring them. This is no quick short-hop airplane book by any stretch of the imagination! David Quammen’s style is immanently readable, and I look forward to reading more by him.
My rating: Very highly recommended!
Amazon link: The Song of the Dodo: Island Biogeography in an Age of Extinction