Abstract
The stability of consumer–resource systems can depend on the form of feeding interactions (i.e. functional responses). Size‐based models predict interactions – and thus stability – based on consumer–resource size ratios. However, little is known about how interaction contexts (e.g. simple or complex habitats) might alter scaling relationships. Addressing this, we experimentally measured interactions between a large size range of aquatic predators (4–6400 mg over 1347 feeding trials) and an invasive prey that transitions among habitats: from the water column (3D interactions) to simple and complex benthic substrates (2D interactions). Simple and complex substrates mediated successive reductions in capture rates – particularly around the unimodal optimum – and promoted prey population stability in model simulations. Many real consumer–resource systems transition between 2D and 3D interactions, and along complexity gradients. Thus, Context‐Dependent Scaling ( CDS ) of feeding interactions could represent an unrecognised aspect of food webs, and quantifying the extent of CDS might enhance predictive ecology.