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Foraging Behavior And Switching By The Grasshopper Sparrow Ammodramus Savannarum Searching For Multiple Prey In A Heterogeneous Environment, Anthony Joern

School of Biological Sciences: Faculty Publications

Switching among four alternative grasshopper species by the grasshop- per sparrow (Ammodramus savannarum) through frequency-dependent predation was ex- amined. Grasshoppers were presented against a heterogeneous natural background in an outdoor aviary where total density was held constant but relative density of each grasshopper species varied. Switching among prey, primarily between two of the four species, and inter-bird variability in switching was observed. Species-specific prefer- ences and interactions among the alternative grasshopper species affected the final diet choice as one grasshopper species was always preferentially selected and another disregarded independent of changes in relative density. Attributes of avian foraging behavior, including: …