Temperature effects on anti-predator behaviour in Rhabdophis tigrinus, a snake with toxic nuchal glands

Citation
A. Mori et Gm. Burghardt, Temperature effects on anti-predator behaviour in Rhabdophis tigrinus, a snake with toxic nuchal glands, ETHOLOGY, 107(9), 2001, pp. 795-811
Citations number
51
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences","Neurosciences & Behavoir
Journal title
ETHOLOGY
ISSN journal
0179-1613 → ACNP
Volume
107
Issue
9
Year of publication
2001
Pages
795 - 811
Database
ISI
SICI code
0179-1613(200109)107:9<795:TEOABI>2.0.ZU;2-4
Abstract
Many contextual factors affect the anti-predator behaviour of animals. In e ctotherms, in which most physiological activities depend on body temperatur e, ambient temperature is one of the most important of these factors. We ex amined the effects of temperature on the anti-predator behaviour of an ecto therm, the Japanese grass snake (Rhabdophis tigrinus). This species has a l arge repertoire of anti-predator behavioural responses. Among these respons es are several anti-predator displays that appear to be unique to this spec ies and perhaps others in a small group of closely related species possessi ng nuchal glands containing toxic secretions that may be derived from their toxic toad diet. Snakes were tested at room temperatures of 14, 22 and 30 degreesC with order of temperatures balanced. A long wand modified to simul ate initial contact by a predator was used as the stimulus. Snakes exhibite d rather passive responses (neck flatten, body flatten, neck arch and immob ile) more frequently at low temperatures, and fled more frequently at high temperatures. The dorsal facing posture, a characteristic posture directed against the stimulus, was observed more frequently at low temperatures. Thr eatening, assertive responses such as strike were rarely observed. These re sults showed that R. tigrinus shifts its antipredator behaviour from multip le passive responses to active flight responses with increasing temperature . This snake species thus appears to rely more on its nuchal glands as a pr edator deterrent at low ambient temperatures. Consistent individual variati on was also observed, and its adaptive and causal bases are discussed.