Experimental determination of the spatial scale of a prey patch from the predator’s perspective

• Published in: Oecologia Vol. 174; no. 3; pp. 723 - 729
• Main Authors: Birk, Matthew A, White, J. Wilson
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.03.2014; Springer; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal, plant and microbial ecology; Animals; BEHAVIORAL ECOLOGY; Behavioral ecology - Original research; Biological and medical sciences; Biomedical and Life Sciences; Coral reefs; Daphnia; Density; ecologists; Ecology; Ecosystem; Experimentation; Fish; Fish scales; Fishes; Foraging; Fresh water ecosystems; Fundamental and applied biological sciences. Psychology; General aspects; habitats; Hydrology/Water Resources; landscapes; Life Sciences; Male; Marine ecology; Mortality; Plant Sciences; Poecilia; Poecilia reticulata; Predation; Predators; Predatory Behavior; Prey; Synecology; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Zooplankton; Density-dependent mortality; Foraging theory; Scale dependence; Patch selection; Theory; Mortality; Spatial scale; Experimental study; Foraging behavior; Freshwater environment; Prey; Vertebrata; Perspective; Pisces; Density dependence; Poecilia reticulata; Predator
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s00442-013-2818-1

Foraging theory predicts that predators should prefer foraging in habitat patches with higher prey densities. However, density depends on the spatial scale at which a “patch” is defined by an observer. Ecologists strive to measure prey densities at the same scale that predators do, but many natural landscapes lack obvious, well-defined prey patches. Thus one must determine the scale at which predators define patches of prey. We estimated the scale at which guppies, Poecilia reticulata, selected patches of zooplankton prey using a behavioral assay. Guppies could choose between two prey arrays, each manipulated to have a density that depended on the spatial scale at which density was calculated. We estimated the scale of guppy foraging by comparing guppy preferences across a series of trials in which we systematically varied the scale associated with “high” prey density. This approach enables the application of foraging theory to non-discrete habitats and prey landscapes.