IJEE Soapbox: habitats and seasons

All naturalists know that the world is heterogeneous in space and time, for almost any physical property and at almost any scale one cares to examine. The diversity of life—the number of species that exist, and how they are organized into complex communities—must reflect in some way the magnitude and structure of that hetereogeneity. Ecologists use random quadrats to sample the world. The insightful set of essays in this compendium bring out the many consequences of the fact that organisms, by contrast, judiciously choose habitats to live in from the palette provided by environmental heterogeneity, and that habitat selection can have profound consequences for many aspects of ecological systems. To understand the life of an organism, we have to look at the world through its own eyes, and to recognize that in effect organisms are their own quadrats, which they place in a decidedly non-random way upon the landscape. After reading through the articles in this special issue on habitat selection, I decided to read again the original writings of Steve Fretwell, who coined the terms “ideal free distribution” and “ideal despotic distribution” that are such a familiar part of today’s ecological and behavioral lexicon. The original paper (Fretwell and Lucas, 1969) does not seem to be readily available online. [Ironically, although one cannot get to the paper on the Web of Science, one can get a citation to Fretwell (1991)—an essay he wrote for Current