On the Allometric Scaling of Resource Intake Under Limiting Conditions

TL;DR

This paper presents a new model combining body size scaling and resource availability to better predict individual resource intake rates, accounting for body size effects under limiting conditions.

Contribution

The authors develop a unified mathematical model integrating Kleiber scaling and Holling responses to explain resource intake under limiting conditions, supported by empirical data.

Findings

The model predicts a concave relationship between intake and body size on a log-log scale.

Empirical data from macro-invertebrates support the model's predictions.

The model accounts for deviations from simple power-law scaling under resource limitations.

Abstract

Individual resource intake rates are known to depend on both individual body size and resource availability. Here, we have developed a model to integrate these two drivers, accounting explicitly for the scaling of perceived resource availability with individual body size. The model merges a Kleiber-like scaling law with Holling functional responses into a single mathematical framework, involving both body-size the density of resources. When the availability of resources is held constant the model predicts a relationship between resource intake rates and body sizes whose log-log graph is a concave curve. The significant deviation from a power law accounts for the body size dependency of resource limitations. The model results are consistent with data from both a laboratory experiment on benthic macro-invertebrates and the available literature.