COMPLEXITY IS IN THE EYE OF THE BEHOLDER

Abstract

Complex ity in biological systems cannot be measured by the number of species present, even though th is parameter is trad i· tionally used as an intu it ive measure of complexity. What matters in complexity is how many kinds of organisms a given organism recognizes in its interactions with those organisms. likewise, what matters is the number of species that a species is linked to in the habitat, since this number determines in part how much of a change in one species will be perceived as a change by other species. These generalities are illustrated with examples from the saturniid moth caterpillars and their predators and parasites in a Costa Rican dry forest in Santa Rosa National Park. It is possible to conclude that, for example, to a foraging bird, a tropical habitat rich in caterpillar species may be no more complex than is an extra·tropical habitat poor in species; ten species of green and edible caterpillars may be perceived as identical to 100 spe· cies of green and edible caterpillars.