Current Research
How do native predators learn to consume invasive prey, especially those with specialized defenses?
There has been a lot of focus on how prey avoids predators through phenotypic plasticity. Predators on the other hand, are often treated more or less as fixed units. Even though there is strong evidence for a predator-prey arms race, prey are thought to adapt faster to predators than predators to prey, since it is worse to loose your life than to miss a dinner (the life-dinner principle). Although this may be true, many predators show great phenotypic plasticity, if they did not, invasive predators would not be a problem!
When invasive prey proliferate, the food base in an invaded ecosystem change. According to optimal foraging theory, predators should switch to the food that is most profitable (i.e. abundant, good energetic value per effort). In Northeast United States many mollusks have invaded over different time-scales. I want to find out if the predators are getting better at consuming the invasive mollusks over time. Mollusks are an interesting group of invaders to study, since they often become extremely abundant and have drastic effects on ecosystem functioning in the invaded habitat. They also have specialized defenses as shells or distasteful slime that may discourage predators at first. I hypothesize that different guilds and taxa of predators will learn to consume these mollusks, but that specialized predators (i.e. molluskivores) will learn faster than generalist predators. Understanding how different, native predators learn to consume an invasive species is important since invasive species change invaded ecosystems and wipe out native species when they attain high densities. If we have information on how the native predator community may respond to a new resource over time, we can predict how long an invasive species will have a population over a critical density where native species go extinct. |
Selected Publications
- Carlsson, N.O.L, and J.O. Lacoursière. 2005. Herbivory on aquatic vascular plants by the introduced golden apple snail (Pomacea canaliculata) in Lao PDR. Biological Invasions 7(3).
- Carlsson, N.O.L., C. Brönmark, and L.-A. Hansson. 2004. Invading Herbivory: The golden apple snail alters ecosystem functioning in Asian wetlands. Ecology 85(6):1575-1580.
- Carlsson, N.O.L., Å. Kestrup, M. Mårtensson, and P. Nyström. 2004. Lethal and non-lethal effects of multiple indigenous predators on the invasive golden apple snail (Pomacea canaliculata). Freshwater Biology 49:1269-1279.
- Carlsson, N.O.L, and C. Brönmark. 2006. Size-dependent effects of a herbivorous invasive snail (Pomacea canaliculata) on macrophytes and periphyton in Asian wetlands. Freshwater Biology, 51(4):695-704.
- Book chapter:
Carlsson, N.O.L. 2006. Invasive golden apple snails are threatening natural ecosystems in Southeast Asia. pp. 61-72. In: R. C. Joshi, L. S. Sebastian (ed.). Global Advances in Ecology and Management of Golden Apple Snails. Philippines Rice Research Institute, Nueva Ecija.
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