Experimental demonstration of population extinction due to a predator-driven Allee effect
Article first published online: 19 JAN 2010
© 2010 The Authors. Journal compilation © 2010 British Ecological Society
Journal of Animal Ecology
Volume 79, Issue 3, pages 633–639, May 2010
How to Cite
Kramer, A. M. and Drake, J. M. (2010), Experimental demonstration of population extinction due to a predator-driven Allee effect. Journal of Animal Ecology, 79: 633–639. doi: 10.1111/j.1365-2656.2009.01657.x
- Issue published online: 22 MAR 2010
- Article first published online: 19 JAN 2010
- Received 9 April 2009; accepted 14 December 2009 Handling Editor: Andrew Beckerman
- Allee effect;
- critical density;
- functional response;
- predator satiation
1. Allee effects may result in negative growth rates at low population density, with important implications for conservation and management of exploited populations. Theory predicts prey populations will exhibit Allee effects when their predator exhibits a Type II functional response, but empirical evidence linking this positively density-dependent variation in predator-induced individual mortality to population growth rate and probability of extinction is lacking.
2. Here, we report a demonstration of extinction due to predator-driven Allee effects in an experimental Daphnia-Chaoborus system. A component Allee effect caused by higher predation rates at low Daphnia density led to positive density dependence in per capita growth rate and accelerated extinction rate at low density.
3. A stochastic model of the process revealed how the critical density below which population growth is negative depends on the mechanistic details of the predator–prey interaction.
4. The ubiquity of predator–prey interactions and saturating functional responses suggests predator-driven Allee effects are potentially important in determining extinction risk of a large number of species.