Effects of prey behavior and woody habitat complexity on foraging of two freshwater piscivores

We examined the predator-prey interaction between two freshwater piscivores and two prey species with contrasting behavioral traits in response to a gradient of coarse woody habitat complexity.  Foraging success of individual largemouth bass or muskellunge and either golden shiner or bluegill sunfish prey were observed across 4 levels of coarse woody habitat complexity in a factorial experiment in laboratory pools (1.9 m diameter, 30 cm depth).  The success of largemouth bass foraging increased linearly with increasing habitat complexity for golden shiner prey while habitat complexity had no affect upon feeding with bluegill prey. Muskellunge foraging success was unaffected by habitat complexity across both prey species and was uniformly higher when feeding on golden shiner.  Behavioral observations of golden shiners when preyed upon by largemouth bass showed disruptions in schooling behavior, greater proximity to predators and no changes in activity rates with increasing habitat complexity.  In contrast, when preyed upon by largemouth bass bluegill schooled more tightly, increased their distance from predators and reduced activity rates with increasing habitat complexity.  When preyed upon by muskellunge, patterns in prey behavior were similar but of a smaller magnitude.  These results highlight the importance of species-specific behaviors to understanding the consequences of habitat change.