Present address: Department of Ecology and Evolutionary Biology, Earth and Marine Science A308, UC Santa Cruz, Santa Cruz, CA 95064 USA.
Patterns of island occupancy in bats: influences of area and isolation on insular incidence of volant mammals
Version of Record online: 21 MAY 2008
© 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd
Global Ecology and Biogeography
Volume 17, Issue 5, pages 622–632, September 2008
How to Cite
Frick, W. F., Hayes, J. P. and Heady III, P. A. (2008), Patterns of island occupancy in bats: influences of area and isolation on insular incidence of volant mammals. Global Ecology and Biogeography, 17: 622–632. doi: 10.1111/j.1466-8238.2008.00401.x
- Issue online: 12 AUG 2008
- Version of Record online: 21 MAY 2008
- Baja California;
- compensatory effects;
- incidence functions;
- probability of occurrence
Aim The influence of landscape structure on the distribution patterns of bats remains poorly understood for many species. This study investigates the relationship between area and isolation of islands and the probability of occurrence of six bat species to determine whether persistence and immigration abilities vary among bat species and foraging guilds.
Location Thirty-two islands in the Gulf of California near the Baja California peninsula in north-west Mexico.
Methods Using logistic regression and Akaike information criterion (AIC) model selection, we compared five a priori models for each of six bat species to explain patterns of island occupancy, including random patterns, minimum area effects, maximum isolation effects, additive area and isolation effects and compensatory area and isolation effects.
Results Five species of insectivorous bats (Pipistrellus hesperus, Myotis californicus, Macrotus californicus, Antrozous pallidus and Mormoops megalophylla) displayed minimum area thresholds on incidence. The probability of occurrence tended to decrease at moderate distances of isolation (c. 10–15 km) for these species (excepting A. pallidus). The distributions of two non-insectivorous species (Leptonycteris curasoae and Myotis vivesi) were not influenced by island size and isolation.
Main conclusions Minimum area thresholds on incidence suggest that island occupancy by insectivorous bats may be limited by resource requirements. Islands smaller than 100 ha typically did not support occupancy or use by insectivorous bats, except at minimal isolation distances. Insectivorous bat species may also be more sensitive to moderate levels of habitat isolation in some landscape contexts than previously expected. Our results suggest that differences in foraging habits may have important implications for understanding the distribution patterns of bats.