Hooding behaviour in the South American colubrid genus Philodryas, based on field observations conducted on the Chilean long-tailed snake P. chamissonis

2015-02-06T09:16:49Z (GMT) by Manuel Jara Daniel Pincheira-Donoso
<p>Animal species have evolved a remarkable diversity of defensive phenotypic strategies aimed to deceive<br>predators and other forms of danger. By relying on deception, these adaptations increase the<br>chances of avoiding physical contact that may otherwise have very high fitness costs. One such deceptive<br>behaviour is the popularly-known neck flattening, or “hooding”, observed in some snakes.<br>Hooding consists in the lateral expansion and dorso-ventral flattening of the neck, which creates the<br>impression of a bigger opponent during confrontations. This trait is highly characteristic of cobras<br>(Elapidae family). However, neck flattening is not exclusive to elapids, and has in fact been observed<br>in a few other snake lineages, including some species of the families Lamprophiidae and Colubridae.<br>Here, we present the first report of hooding behaviour in the South American colubrid genus<br><em>Philodryas</em>, based on field observations conducted on the Chilean species <em>P. chamissonis</em> (the longtailed<br>snake). Our report adds to the few cases in which this deceptive behaviour has been observed in<br>snakes outside the cobra family.</p> <p> </p>