Velvet Gecko Essay

Do Velvet Gecko (Oedura lesueurii) Exhibit Specialized or Generalized Anti-Snake Behavior? The main question this study asked was do velvet geckos discriminate amongst snake species and display antipredator behaviors according to the ‘threat sensitivity’ hypothesis (i.e. in a graded fashion depending upon the degree of threat posed by a particular snake species)? The authors hypothesized that velvet geckos should display general antipredator behaviors to the scent of syntopic elapid snakes, irrespective of how frequently they are encountered, or the degree of threat they pose (in line with the ‘multipredator’ hypothesis). The prediction was that since most snake species in Australia eat lizards, including geckos, and are therefore potentially dangerous, velvet geckos should display generalized rather than species-specific antipredator behaviors. The antipredator behaviors that were examined included: tongue-extrusion, tail waving, tail vibrations, reversing, lunging, running, freezing in place, slow motion, crawling and walking. These behaviors were quantified to evaluate the degree of caution (threat evaluation) the velvet geckos exhibited when encountering …show more content…
It has been shown that several predatory species have evolved to be especially attuned to movement and non-moving stimuli ‘cease to exist’. This suggests that black bears may be restricted by the evolutionary foraging ecology of their lineages which require rapid movements to be made for another organism to be sensed. A black bear’s dichromatic vision may be further hindrance in evolving snake discrimination abilities as they are unable to identify the aposematism characteristic of venomous snakes that other species (trichromats, such as primates) utilize to discriminate amongst snake