The Daily Bulletin Archive

Please join the Biology Department for the seminar "Living below the Poverty Line? How Prey Patches Allow Consumers to Thrive in Regions of Low Mean Prey Density," presented by Audrey Reid, Ph.D. candidate from the Biology Department at the University of Toronto Mississauga, on Monday, September 15, from 3:30 to 4:30 p.m. in Technology Building 160.

All faculty, staff, and students are welcome.

Seminar Abstract
In aquatic ecosystems, it has often been observed that there are not enough prey to support the growth and feeding of a predator population. Yet predators obviously survive and thrive in these ecosystems. Is it because the full diet of the predator is not known? Are growth and consumption calculations incorrect? Apparently not, according to the literature. Using Daphnia pulex as my model consumer, I test the hypothesis that the problem is based on our usage of average concentrations of organisms, as often measured in the field by investigators. These low mean prey concentrations are inadequate to meet predator growth needs. Yet we know that, in fact, prey and consumers are distributed in patches across space, and it is only by having access to locally high concentrations of prey that predators are able to meet their energy requirements. I conclude that the spatial structure of aquatic populations must be accurately measured in order to understand and predict the productive capacity of lakes and rivers.