Niche breadth and geographical range: ecological compensation for geographical rarity in rainforest frogs.
We investigated the relationship between diet specialization and geographical range in Cophixalus, a genus of microhylid frogs from the Wet Tropics of northern Queensland, Australia. The geographical ranges of these species vary from a few square kilometres in species restricted to a single mountain top to the entire region for the widespread species. Although macroecological theory predicts that species with broad niches should have the largest geographical ranges, we found the opposite: geographically rare species were diet generalists and widespread species were diet specialists. We argue that this pattern is a product of extinction filtering, whereby geographically rare and therefore extinction-prone species are more likely to persist if they are diet generalists.
Williams
Yvette M
YM
School of Marine and Tropical Biology, James Cook University, Townsville 4811, Australia. yvette.williams@jcu.edu.au
Williams
Stephen E
SE
Alford
Ross A
RA
Waycott
Michelle
M
Johnson
Christopher N
CN
D000818:Animals; D001001:Anura / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D017753:Ecosystem; D005843:Geography; D007448:Invertebrates; D011156:Population Density; D011793:Queensland