Data from: The mechanics of predator-prey interactions: first principles of physics predict predator-prey size ratios

1. Robust predictions of predator-prey interactions are fundamental for
the understanding of food webs, their structure, dynamics, resistance to
species loss, response to invasions and ecosystem function. Most current
food web models measure parameters at the food web level to predict
patterns at the same level. Thus, they are sensitive to the quality of the
data, and may be ineffective in predicting non-observed interactions and
disturbed food webs. There is a need for mechanistic models that predict
the occurrence of a predator-prey interaction based on lower levels of
organization (i.e., the traits of organisms) and the properties of their
environment. 2. Here, we present such a model that focuses on the
predation act itself. We built a Newtonian, mechanical model for the
processes of searching, capturing and handling of a prey item by a
predator. Associated with general metabolic laws, we predict the net
energy gain from predation for pairs of pelagic or flying predator species
and their prey depending on their body sizes. 3. Predicted interactions
match well with data from the most extensive predator-prey database, and
overall model accuracy is greater than the allometric niche model. 4. Our
model shows that it is possible to accurately predict the structure of
food webs using only a few mechanical traits. It underlines the importance
of physical constraints in structuring food webs.