THE INFLUENCE OF GUT MORPHOLOGY ON DIGESTION TIME IN RAPTORS

1. Raptor species (Falconiformes and Strigiformes) have been shown to differ in intestine length by as much as 50% independent of body size and these differences are thought to be related to foraging strategy. 2. Unless mte of food passage is reduced, raptor species with short digestive tracts would be predicted to have lower digestive efficiency. 3. European sparrowhawk, peregrine and hobby have a short small intestine relative to body size resulting in rapid digesta throughput and a short food retention time. The common buzzard, European kestrel and red kite have a long, high-capacity digestive tract with a corresponding long food retention time. 4. There was no evidence for a compensatory mechanism by which food passage could be slowed in species with a relatively short digestive tract.