Die Bedeutung der Haupt- und Nebenaugen für die photomenotaktische Orientierung der Trichterspinne Agelena labyrinthica (Cl.)1

Yawning in reptiles was investigated in field observations of various lizard and tortoise species and in laboratory experiments with the tortoises Testudo h. hermanni and Emys orbicularis. In the experiments the animals' reactions to various conditions of temperature, air O₂ and CO₂ content, fatigue and hunger, were tested. Yawning and related or similar motor patterns are described and discussed.