PARENT SESSION
Contributed Oral Session 78: Evolutionary Ecology: Genetics
Wednesday, August 10, 8:00 AM - 11:30 AM, Meeting Room 516 D, Level 5, Palais des congrès de Montréal
The consequences of reproductive asynchrony on the ecology of small populations.
Ries, Leslie*,1, Calabrese, Justin1, Fagan, William1, Matter, Steve 2, Debinski, Diane3, Roy, David4, 1 University of Maryland, College Park, MD, USA2 University of Cincinnati, Cincinnati, OH, USA3 Iowa State University, Ames, IA, USA4 Center for Ecology and Hydrology, Huntingdon, Cambridgeshire, UK
ABSTRACT- The asynchronous reproduction of individuals throughout a breeding season has traditionally been viewed as an advantageous bet-hedging strategy in temporally variable environments. In contrast, recent theoretical work has shown that reproductive asynchrony can cause small populations to crash via an Allee effect. Butterflies, which generally exhibit a high degree of reproductive asynchrony, are one of the most extensively monitored groups, and are often used as indicators of ecological decline. However, the asynchronous nature of their reproduction has rarely been incorporated into estimates of their population sizes or viability. We have been developing methods to test the reproductive asynchrony model on a variety of butterfly data sets and found that there can be profound consequences for population dynamics. Using data from the British Monitoring Scheme, we show that the degree of asynchrony has a substantial impact on the estimates of total population size, which has important impacts for both monitoring and species recovery plans. Then, using a separate data set on female mating rates in the North American butterfly Parnassius smintheus, we show that there is an interaction between density, asynchrony and mating success. The results of our analyses suggest that reproductive asynchrony can have a substantial influence on population dynamics of species where adults are reproductively active for only a small portion of the total mating season.
Key words: reproductive asynchrony, population dynamics, butterfly, Allee effect