Abstract

This book comprises forty-one essays, some of them about solar eclipses, space stations, mushrooms, and refugees, but the majority focus on animals, mostly birds. Macdonald starts each piece with a personal recollection from childhood or adulthood. “Vesper Flights,” for instance—the essay that gives the book its title—begins: “I found a dead swift once, a husk of a bird under a bridge over the River Thames.... I picked it up, held it in my palm... and realised that I didn't know what to do.” The author continues by setting out the little that she did know, before that encounter, about swifts—she knew only that they are very difficult to observe individually because of the velocity and the height of their flights. To her, the swifts had always been like “aliens on earth.”Those birds are known for their peculiar flights at dusk, when they go up almost vertically into the sky. Scientists used to believe that they went up to sleep; but, at the end of the 1970s, in order to study the interaction between birds and airplanes, Luit Buurma of the Netherlands made radar observations that showed the swifts do not sleep at high altitude. The hypothesis of Buurma and other scientists is that they go up to forecast the weather. In the convective boundary layer, the winds are unaffected by geographic components, and, at that altitude, the swifts may also orient themselves better, thanks in part to the polarized light that is clearest at twilight. “What they are doing,” Macdonald summarizes these findings, “is flying so high they can work out exactly where they are, to know what they should do next.”Macdonald was trained in the history of science, which explains her taste for telling stories in which she explains how we come to know other animal species. She stresses the importance of technical devices in the construction of knowledge (without military radar, scientists would never have known where the swifts were flying). In each chapter, she also underscores the problem of what she aptly calls “multispecies social etiquette”: it is such a problem (how to avoid collisions with birds, a particular kind of social interaction) that moved scientists to study swifts in the first place. I much enjoyed reading these parts of each chapter. I was less convinced, however, by the morals that she draws from animal behaviors—for example: “Swifts are my fable of community, teaching us about how to make right decisions in the face of oncoming bad weather, in the face of clouds that sit like dark rubble on our horizon.” What makes me uncomfortable with such general conclusions is that they could as well be reached without the birds.