PREY SIZE DETERMINES HANDLING AND CAPTURE TACTICS IN THE WESTERN GREBE

Abstract

To investigate the feeding behavior of the Western Grebe (Aechmophorous occidentalis), I observed the actions of one kept in a laboratory pool and fed fish of various sizes and in varying numbers during four trials per day. The grebe consumed fish under 4 cm in length underwater but brought all fish longer that 5 cm to the surface so they could be oriented for swallowing headfirst. The Western Grebe is likely gape-limited in its choice of fish and can only ingest prey that can be swallowed easily.