Provocative stabs at answering the really big questions regarding wildlife biology, the ones seemingly skipped over when the Victorians tidied up their discipline of natural history.
What are the answers to some of the obvious questions regarding the evolution of creatures (such as why mammals dominate the savanna and reptiles the swamps)? Why are the cold bloods more successful in the struggle for life in a small scale, and why are birds small, and why are there ostriches at all? Lavers (Geography/Univ. of Nottingham) approaches all these unanswered mysteries through the lens of garnering and rationing energy, and his results chime true. Size and energy use figure prominently here, be it regarding gas-guzzling elephants or turbo-charged hummingbirds. Lavers follows the journey from cold-bloodedness to warm-bloodedness, “souping up the metabolic engines.” Yet there are clearly times when cold-bloodedness wins out, as for those creatures that must endure long periods of drought and starvation. Along the way, Lavers introduces readers to a host of wild oddments, from the utterly rude naked mole-rat to creatures that were weird even for being dinosaurs. As for birds, he suggests that they are small because they buy the power of flight relatively cheaply, allowing them to “forage over wide areas, exploit three-dimensional habitats such as forests, escape the attention of ground-living predators, migrate” and flee at little metabolic cost. Of course, you might say, but answers to such questions have never been so conveniently deployed as this. Also, Lavers’s prose is as comfortable as flannel sheets on a cold night and as crisp as starlight. Elephants, by the way, have big ears because it allows them to efficiently shed body heat.
Natural history is one of the few sciences that lends itself to enjoyably larking about ideas and hypotheses as well as having its sober sides, and Lavers takes full advantage of its propensity for entertaining erudition.