In discussing how every species has its niche in the scheme of things, Colinvaux talks of the wolf-spider in the graceful, often amusing style that is characteristic of the book: “Wolf-spidering is a complex job, not something to be undertaken by an amateur.
We might say that there is a profession of wolf-spidering.” This concept—that every species has its niche—and the resulting impact on breeding strategy implies limits to the size of population of a given species and a struggle to decide which family strains will occupy the limited number of spaces in the world.
“Ecology” is a current “in” word, and Colinvaux begins by confessing that he wrote this book in some anger, pointing out that ecology is neither the science of pollution, nor environmental science, nor the science of doom.
He comments: “I take the opportunity to brand as nonsense tales of destroying the atmosphere, killing lakes, and hazarding the world by making it simple.” If there is a bias in the book, it could be labeled pro-Darwinian.
The less the energy available in this system means that small number of individuals can get support.
This means that the big animals will be few in number in their ecosystem.
In an intriguing sidelight, Colinvaux writes of , the dinosaur most often portrayed as stalking about on its hind legs, hideous teeth bared.
Colinvaux notes that more recent reconstructions of the tyrannosaur picture the beast as relatively inactive, spending most of its time lying on its belly (conserving energy), feeding on the sick and dying or on carrion.
One of the most provocative sections of Colinvaux’s book is the title essay, “Why Big Fierce Animals Are Rare,” which discusses the Eltonian pyramid, named for Charles Elton of Oxford.
During a visit to the Arctic island of Spitzbergen, Elton observed how the foxes fed upon the summer birds of the tundra, which in turn fed upon tundra plants or insects and worms.