This example is provided so that non-theorists may see actual applications of the theory previously described. This study considered directly some of the components of Field Sparrow breeding success as a measure of habitat suitability, and found these to vary in a way which was inconsistent with hypotheses that territorial behavior either cues, or limits density. This study provides a valid example of how the problem can be approached and offers a first step in the eventual identification of the role (...) of territorial behavior in the habitat distribution of a common species. (shrink)