PARENT SESSION
Organized Oral Session 45: Evolution in metacommunities: A new framework for species coexistence
Organizer(s): MC Urban and MA Leibold
Thursday, August 11, 8:00 AM - 11:30 AM, Meeting Room 516 A, Level 5, Palais des congrès de Montréal

Adaptive prey strategies in a temporary pond metacommunity.

Urban, Mark^*,1, ¹ Yale University, New Haven, CT

ABSTRACT- Metacommunity theory suggests that regional migration dynamics can modify the outcome of local interspecific interactions. At the same time, local adaptation can alter the strength of interspecific interactions. Such evidence for local evolution has the potential to modify predictions about community dynamics. Here, I evaluate population divergence in a temporary pond metacommunity of spotted salamander larvae (Ambystoma maculatum) in response to two dominant predators (A. opacum and Dytiscus larvae). Field surveys indicated that A. maculatum populations encounter variable predation risk from A. opacum and Dytiscus over relatively fine spatial scales. Previous research showed that A. maculatum larvae exposed to cues from gape-limited A. opacum grew faster than larvae exposed to cues from gape-independent Dytiscus and that growth rates differed among populations. I hypothesized that these divergent growth strategies constituted evidence for an adaptive foraging strategy that promotes early entry into a prey size refuge. To refine this hypothesis, I constructed a quantitative genetic simulation of a multi-predator metacommunity. The parameterized model identified a fitness minimum such that prey populations adopted either a low- or high-risk foraging strategy depending on predator composition. Next, I evaluated foraging activity and survival among populations with different predator communities. Consistent with model expectations, A. maculatum populations sympatric with the gape-limited predator, A. opacum, foraged most frequently and suffered the highest predator-induced mortality during early development. Evidence suggests that prey populations have evolved different foraging strategies depending on local predator composition. Evidence for the local adaptation of interaction traits supports application of an evolving metacommunity perspective. By incorporating genetics, an evolving metacommunity perspective has the potential to improve upon predictions of multi-species interactions across multiple scales.

Key words: evolving metacommunity, community genetics, evolutionary ecology, predator-prey interactions