Anticipatory Reproduction and Population Growth in Seed Predators
Stan Boutin,1*
Lucas A. Wauters,2
Andrew G. McAdam,3
Murray M. Humphries,4
Guido Tosi,2
André A. Dhondt5,6
Mast seeding, the intermittent, synchronous production of large seed crops by a population of plants, is a well-known example of resource pulses that create lagged responses in successive trophic levels of ecological communities. These lags arise because seed predators are thought capable of increasing reproduction and population size only after the resource pulse is available for consumption. The resulting satiation of predators is a widely cited explanation for the evolution of masting. Our study shows that both American and Eurasian tree squirrels anticipate resource pulses and increase reproductive output before a masting event, thereby increasing population size in synchrony with the resource pulse and eliminating the population lag thought to be universal in resource pulse systems.
1 Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada.
2 Department of Environment, Health, and Safety, University of Insubria, Varese, Via J. H. Dunant 3, I-21100 Varese, Italy.
3 Ecology, Evolutionary Biology, and Behavior Program, Department of Fisheries and Wildlife, Department of Zoology, 13 Natural Resources Building, Michigan State University, East Lansing, MI 48824, USA.
4 Natural Resource Sciences, Macdonald Campus, McGill University, Ste-Anne-de-Bellevue, Québec H9X 3V9, Canada.
5 Laboratory of Ornithology, Cornell University, 159 Sapsucker Woods Road, Ithaca, NY 14850–1999, USA.
6 Department of Biology, University of Antwerp, B-2610 Wilrijk, Belgium.
* To whom correspondence should be addressed. E-mail: stan.boutin{at}ualberta.ca
