Book Review: The Homing Instinct
By Bernd Heinrich
The great naturalist Bernd Heinrich takes as the subject of his new book The Homing Instinct the vast, perpetual motion of the living world, the massed migrations of the animal world – and the near-magical neuro-circuitry that makes those migrations possible. As in all his other books, he eases into narrative immediacy of his subject with a fluency that’s, to put it mildly, not widely shared among his scientific brethren:
Every fall and spring billions of birds travel to their wintering grounds where they can find food, and in the spring they return to near where they were born in order to nest. In huge tides, partially aided by favorable winds but mostly by their own muscle power, they ply the skies in the day and at night in the Northern and Southern hemispheres, sometimes covering thousands of kilometers in a few days. For the most part, the birds have pinpoint home destinations, places such as a specific woodlot, field, or hedge. In the fall they reverse their journey, though often by a different route, again to reach specific pinpoints in their winter homes. Turtles on the seas accomplish the same navigation feats between breeding and feeding areas.
Those navigational feats are often flat-out astonishing (the feats of those turtles Heinrich mentions are positively mind-boggling; anyone who’s been on the open ocean far from land will viscerally presume they can’t be done – and yet turtles go right on doing them), and long-time readers of this author will know that one of his most pleasing traits is that he never loses his ability to feel that astonishment:
The magnitude of birds’ migratory performances staggers our imagination, in terms of both physical exertion and feats of navigation, because they are vastly superior to anything we could, as individuals, accomplish. Bird migration, as we now understand it, for centuries seemed impossible because we used ourselves as the standard, and that of turtles was not even considered. The animals’ performances would still seem impossible, given our ignorance and arrogance, were it not for proof from countless research experiments.
The Homing Instinct ranges wide over the whole of the animal kingdom, looking at a broad spectrum of migrations, from fish to humans to birds to honeybees, whose intricately complex communications help to facilitate their many new homecomings, as for instance in the hollow a tree that most of the swarm’s individual members have never seen and should thus fear:
On their own, each of the thousands of bees would be unlikely to find it. Nevertheless, it is impressive to see how they quickly enter; indeed, they literally stream into their new home. That is possible because the scouts alight at or in the home entrance, raise their abdomens into the air, an then release the scent from their Nasonov glands. They beat their wings, which creates an air current that spreads the scent, and the swarm follows the scent plumes to its source, the entrance to their new home.
The Homing Instinct doesn’t deal only with the science of getting to and from far-distant destinations; Heinrich also explores the nature of destinations themselves. What is the meaning of home? What do various kinds of animals (ravens make their appearance here, and of course that famous home-builder, the beaver) feel when they think of home? What logics govern the making, expanding, or abandoning of homes? As usual, Heinrich seems very nearly omniscient, and as usual, his prose sparkles with both factual insights and personal shadings. This is an author whose every book is a treasure, although none has had so subtly grand a scope as this one.