SREL Reprint #1011




Blue Tails and Autotomy: Enhancement of Predation Avoidance in Juvenile Skinks

William E. Cooper, Jr., & Laurie J. Vitt



Blue tail coloration in hatchling skinks (Eumeces fasciatus and E. laticeps) appears to be an antipredatory adaption that distracts attention away from the body to the tail.  The tail itself serves as a decoy that may be autotomized as a final defense against capture.  The effectiveness of intact tails in deflecting attacks from the body was 50% against scarlet kingsnakes in the experimental conditions used.  Brightness rather than hue presumably accounts for the higher attack frequency on blue than black tails in this study, but the blue color may have evolved in response to avian predation.

Repeated predation without ill effects by several predators allows rejection of the hypothesis that the blue tail is aposematic for the predators tested.  The hypothesis that blue tails provide stimuli inhibiting aggression or predation by adult male conspecifics is untenable for E. laticeps because adult males readily eat intact hatchlings.  Although this study provides no statistical evidence that blue tail coloration inhibits attach by female E. laticeps on hatchlings, the trend of predation rates on blue- and black-tailed hatchlings is in the direction predicted for inhibition.

SREL Reprint #1011

Cooper, W.E., Jr. and L.J. Vitt. 1985. Blue tails and autonomy: enhancement of predation avoidance in juvenile skinks. Zeitschrift fuer Tierpsychologie 70:265-276.

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