When Benjamin B. Beck wrote _Animal Tool Behavior_ in 1980, it listed hundreds of ways animals, from insects to apes, used tools to do everything from catch prey to brush away flies. It contained all the examples Beck could find in the literature. It proved to be an inspiration to researchers, who more carefully looked for examples and documented them. Thus it was inevitable that the book would go out of date and need a revision because of its own success. Now there is _Animal Tool Behavior: The Use and Manufacture of Tools by Animals_ (The Johns Hopkins University Press) to bring everything up to date, in fact tripling the number of examples found in Beck's original. Beck is again the author, but he has coauthors this time; he was a graduate advisor and mentor for Robert W. Shumaker, who in turn played the same role for Kristina Walkup. Thus the authors say happily in their acknowledgments, "We are three generations of scientists." This comprehensive and handsome revision makes clear that the partnership has been productive, that biologists in the field have seen more examples of tool use because they were looking for them, and that those animals have been busy using sticks, stones, leaves, thorns, and more as they get their livings. It is also clear that tool use, long ago thought to be a hallmark unique to the human animal (an animal whose extensive tool use is not included in this volume for obvious reasons) is widespread, from insects and crabs to chimpanzees.
In the introduction, the authors tackle the problem of definition; what is tool use? The problem is difficult. A clear definition is just a start. The authors further classify tool use into modes of use. The modes include Drop, Throw, Brandish, Pound, Pry, Dig, Jab, Reach, Rub, Wipe, and Block, to list just a few (busy, busy beasts). The main body of the work consists, of course, of the examples of tool use. There are respective chapters devoted to: invertebrates; fish, amphibians, reptiles, and birds; non-primate mammals; prosimians and monkeys; and apes. It is no surprise that the first of these chapters is shorter than the subsequent ones, nor that the chapter on apes is about as long as all the others together. There are so many examples, and many of them are surprising and funny, all the more so for being described with clinical scientific precision. Here is a typical listing, under "Bait, Entice:" "Male spiders of the genus _Pisaura_ capture and present flies to females during courtship. If the female is receptive, she begins to eat the fly and the male has about an hour to copulate without danger of being devoured by the larger female (Bristowe 1929, 1971)." Many of the examples given here are just that brief; for more information you would have to go to the extensive literature referenced here, since this volume concentrates on listing and cataloging. A female water strider carries the male who copulates with her for hours. This would not be the use of a tool, except carrying the male around keeps other males from harassing her, thus allowing her to forage. The hermit crabs of a particular species congregate when there is a new shell available. "The dominant crab occupies the newly available shell, if it is suitable, and the other crabs begin a frantic sequence of shell exchange." Herons use bread as a bait to get fish. Otters do a backstroke while balancing a rock on their chests, and use it as an anvil on which they smash mollusks. A sandhill crane uses a towel to dry itself after swimming. Wild African elephants drop logs or rocks onto electric fences to break the fence or the circuit. It is clear over and over that biological researchers in the field are at risk: "A bird referred to as a `black eagle' (species not reported) in Rhodesia Dropped [the book capitalizes tool modes] eleven sticks toward researchers investigating its nest." Capuchin, howler, colobus, and squirrel monkeys all do the same sort of dropping, as do gibbons and many others. A researcher reported that an elephant threw at her "large stones, sticks, a Kodak film box, my own sandal, and a wildebeest bone." A gibbon stimulated its genitals by rubbing a stick on them. Orangutans "Rubbed or Wiped their own genitalia with inanimate and animate objects, for example, a cat." Bonobos "were observed Throwing unripe fruit at a tortoise."
The long lists of such behaviors are the meat of the book. The authors admit that they have not analyzed the "ontogenic, ecological, evolutionary, and cognitive aspects of tool behavior." In a final chapter about tool myths, they do blast the idea that only primates use tools. They also show that tool use does not mean that tool users are any smarter than non-tool users, and that "intelligence" and tool use need to be untangled from each other's definitions. There is little theorizing here, but the astonishing wealth of examples will be of great use to those thinking about cognition. Reading about how busy all these tool-users are is a delight, an introduction to a unique way of regarding a fascinating aspect of animal behavior.