To Be or Not to Be – Coral Snake Edition

Model coral snake waiting for would-be predators.

Study by Elizabeth Luotto, Kackenzie Korbel, & Logan Goettl

Mimicry is relatively common in the animal world as it offers a less energetically expensive form of defense.  The physical appearance of a mimic, such as the coloring or banding, resembles a dangerous or defended model species.  Mimics do not have the energetic costs of producing poison or other such defenses as the models do, but they may still benefit by confusing potential predators.  In Palo Verde National Park (PVNP), Costa Rica, the venomous and brightly banded coral snake is abundant.  This coral snake has few natural predators due to the high danger involved with catching and eating it.  However, in PVNP there are very few mimics of the coral snake.  In this study, we wanted to explore how predators interacted with various model snakes that looked both similar and different to the coral snake.  To do this we crafted sets of four model snake types: a coral snake with the traditional black yellow red yellow banding, a mimic coral snake with black red banding, an all red snake, and a brown and black banded snake modeled after the locally abundant Costa Rican cat-eyed snake.  Snakes were set out in three microhabitat locations: by the wetlands, in the forest, and on higher elevation rock faces.  The snakes were checked for marks in the morning and evening to capture interactions from both diurnal and nocturnal predators.  Results of a chi-squared test showed that there was no significant difference between the frequency of attacks based on snake model type.  There was also no significant difference between the amount of harm (cm of snake damaged) based on snake model type (P = 0.1218).  These results support the claim that predators did not avoid coral snakes or their mimics.  We cite these results as a potential explanation for why there is limited abundance of coral snake mimics in PVNP, as there is no apparent benefit or predator avoidance, and suggest this as a future area of research.

Model snakes on the left, and an attacked model on the right.