摘要："A 'competition hypothesis' states that the species in faunas with more species (more diversity) have greater competition, narrower niches, and therefore smaller geographic ranges (less distribution). An alternative 'available space hypothesis' states that species occupy suitable available space without regard to the presence or absence of other species. We use American bats and North American rodents as groups to discriminate between the two hypotheses and see that available space is a better predictor of distribution than is diversity. Thus, the competition hypothesis is weakened and the available space hypothesis is strengthened"--p. [1].
