Karema J. Warr

Smaller predator-prey body size ratios in longer food chains

Maximum food–chain length has been correlated with resource availability, ecosystem size, environmental stability and colonization history. Some of these correlations may result from environmental effects on predator–prey body size ratios. We investigate relationships between maximum food–chain length, predator–prey mass ratios, primary production and environmental stability in marine food webs with a natural history of community assembly. Our analyses provide empirical evidence that smaller mean predator–prey body size ratios are characteristic of more stable environments and that food chains are longer when mean predator–prey body size ratios are small. We conclude that environmental effects on predator–prey body size ratios contribute to observed differences in maximum food–chain length.