Scale of Predator-Prey Interactions

Spatial pattern of predators foraging on prey patches is determined by 3 components of ecological scale: grain (patch size), lag (distance between patches) and extent (distance the interaction is manifested). These scale elements may also depend on prey density. We evaluated the components for predator-prey interactions of blue crabs foraging on clams (Macoma balthica) in Chesapeake Bay using: a large grid of benthic cores for clam density; biotelemetery of crab movement and foraging activity; and field experiments testing spatial effects of crab predation impact on clams. We have also tested effects of ecological scale on predator-prey interactions of eagle rays foraging on infaunal bivalves on a sand flat in New Zealand.


The sandflat habitat: scaling from experiments to conclusions.
Thrush, S.F., R.D. Pridmore, R.G. Bell, V.J. Cummings, P.K. Dayton, R. Ford, J. Grant, M.O. Green, J.E. Hewitt, A.H. Hines, T.M. Hume, S.M. Lawrie, P. Legendre, B.H. McArdle, D. Morrisey, D.C. Schneider, S.J. Turner, R.A. Walters, R.B. Whitlatch, and M.R. Wilkinson. 1997.
Journal of Experimental Marine Biology and Ecology 216:1-9.

Spatial structure of bivalves in a sandflat: scale and generating processes.
Legendre, P., S.F. Thrush, V.J. Cummings, P.K. Dayton, J. Grant, J.E. Hewitt, A.H. Hines, B.H. McArdle, R.D. Pridmore, D.C. Schneider, S.J. Turner, R.B. Whitlatch, and M.R. Wilkinson. 1997.
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Matching the outcome of small-scale density manipulation experiments with larger scale patterns: an example of bivalve adult/juvenile interactions.
Thrush, S.F., J. Hewitt, R. Pridmore, V.J. Cummings, R.B. Whitlatch, P. Legendre, A.H. Hines, P.K. Dayton, S.J. Turner, J. Grant, B. Mc Ardle, D.C. Schneider, and M.R. Wilkinson. 1997.
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Benthic faunal responses to variations in patch density and patch size of a suspension-feeding bivalve inhabiting a New Zealand intertidal sandflat.
Whitlatch, R.B., A.H. Hines, S.F. Thrush, J.E. Hewitt, and V. Cummings. 1997.
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Nonlinear foraging response of a large marine predator to benthic prey: eagle ray pits and infaunal bivalves in a New Zealand sandflat.
Hines, A.H., R.B. Whitlatch, S.F. Thrush, P.K. Dayton, J. Hewitt, V. Cummings, and P. Legendre. 1997.
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Scaling-up from experiments to complex ecological systems: Where to next?
Thrush, S.F., D.C. Scheider, P. Legendre, R.B. Whitlatch, P.K. Dayton, J.E. Hewitt, A.H. Hines, V.J. Cummings, S.M. Lawrie, J. Grant, R.D. Pridmore, S.J. Turner, and B.H. McArdle. 1997.Journal of Experimental Marine Biology and Ecology 216: 243-251.