to load his gun, to squeeze the trigger — but all of this is made possible by energy sources that do not come from his body, but from fossil fuels, from hydroelectric power, or perhaps from other energy sources that exist independently of what he derived from his food. Enormous amounts of energy that have nothing to do with his body’s metabolism, and may be generated and spent thousands of miles away, are required to put him in a position where, with the squeeze of a finger, he can kill a deer, and if he does not, no matter — technology provides him with other food sources.
A few wildlife species have learned to use the most simplistic tools — a small bird found only in the Galapagos Islands can use a stick to probe for insects, for instance, and so can a species of crow found on New Caledonia, and so can the chimpanzee — but not one other species has access to complex tools and the outside energy sources it takes to provide them. A fisherman without a boat and engine, a synthetic rod and reel, perhaps a fish finder, and don’t forget clothing, a cooler, a wristwatch, a car, a choice of hooks and lures, a landing net, perhaps eyeglasses — countless mechanically produced aids whose presence cost him no caloric output — uses far more energy than the energy he derives from the fish he catches and consumes.
The cook may give little thought to the energy that manufactured the can he opens in order to access the soup he is preparing for lunch, not to mention the energy expended by farm machinery to grow the vegetables in the soup, nor to build and run the machinery that moves those vegetables to the factory where more machinery built and using more energy prepares the ingredients to go into cans built and transported.
That transportation uses still more machinery, said machinery representing still more energy both to be made and to function in order to bring the various components together at the factory. Then more energy is required to ship the products in containers that used still more energy to be made and transported to the factory so that they can be sent to a store made from still more machinery built and maintained using still more energy, and so on through a long chain that must occur before the cook ever enters the picture. Even when the can of soup is bought and transported to the kitchen it must be heated on a manufactured stove run on still more energy, additional to what went into the metal from which it is made being taken from the ground, shipped and turned into a stove that is shipped to a store and then to the kitchen, the soup is poured into a bowl and eaten with a spoon that have consumed more energy to be built and shipped, all so a simple lunch can be served. Of course to dump the soup into a pot, and, once heated, into a bowl, and to lift the spoon from bowl to mouth does require metabolic energy, but it is a fraction of the amount of energy from non-metabolic sources that allowed the soup to be there in the first place. And we won’t discuss the dishwashing that follows, or the disposal of the tin can or the manufacture of the soup bowl.
No other species has that option to access energies derived mostly from fossil fuels, but also, to varying degrees, from atomic power, wind and solar power, water-driven turbines, battery power or even tidal or geothermal power. The late John A. Livingston, Canadian naturalist-author, referred to technology as a “prosthesis,” a contrivance that humans have come to depend upon for their survival. He provocatively argued that humans were the first species to domesticate themselves. Most people are not really aware of just how much they depend on technology, and the expenditure of energies that do not derive from their own bodies. It is all taken for granted.
Now consider the cormorant. The energy that she needs to expend in order to survive must be balanced by the energy derived by the food consumed. That is true of every species but humans. Compared to humans, the chain of energy expenditure is relatively simple. The cormorant must swim underwater, pushing against the iner