Berthé Ruben Andres, de Pury Stéphanie, Bleckmann Horst, Westhoff Guido
Department of Comparative Neurophysiology, Institute of Zoology, University Bonn, 53115 Bonn, Germany.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2009 Aug;195(8):753-7. doi: 10.1007/s00359-009-0451-6. Epub 2009 May 22.
If threatened by a human, spitting cobras defend themselves by ejecting their venom toward the face of the antagonist. Circulating head movements of the cobra ensure that the venom is distributed over the face. To assure an optimal distribution of the venom, the amplitudes of head movements should decrease with increasing target distance. To find out whether cobras (Naja pallida and N. nigricollis) adjust their spitting behavior according to target distance we induced spitting from different distances and analyzed their spitting patterns. Our results show that the spray pattern of spitting cobras is not fixed. Instead the snake matches its venom distribution to the size of the target independent of target distance.