Organisms do not live in ecological space as a single entity but have relationships with other organisms. These relationships can take many forms – predator and prey, or symbiosis for example – all of which can have an effect on the way that the organism lives in conjunction with other creatures. For the purpose of this paper, mimesis has been chosen as one of the most interesting and important forms of relationship. The word “mimesis” refers to the ability of one animal to imitate or mimic another species which can be used defensively, aggressively or for reproductive purposes. To illustrate the use of mimesis in nature, the harmless Milk Snake (Lampropeltis triangulum), the mildly toxic False Coral Snake (of the genus Erythrolamprus) and the deadly Coral Snake (Micrurus fulvius) will be examined – the Milk Snake using mimicry of the coloring to appear more dangerous and the deadly Coral Snakes using it to appear less toxic to allow them to get closer to prey.
As would be expected from three species that exhibit mimesis, all three types of snake have a distinctive red skin with yellow and black stripes. Milk snakes grow up to between 20 and 60 inches long and can be found through southern Canada through the United States into some parts of South America (Harper Jr., 2006).Erythrolamprus species usually grow to around 30 inches in length but are more confined to South America, being common in Venezuela, Columbia and Costa Rica (Marevsová, Landová, & Frynta, 2009). Finally, the deadly Coral Snakes are limited to southern parts of the United States – particularly Florida. They are general smaller than the other two species growing up to around 30 inches in length (Harper Jr., 2006). It should be noted that the deadly Coral snake actually has the same banding pattern but in reverse to the harmless milk snake – the milk snake red bands touching the black bands (where the yellow and red do not touch, whilst the deadly snakes have red and yellow banded together (Marevsová, Landová, & Frynta, 2009).
This relationship is interesting because both the deadly snake and the harmless snake are using mimicry to copy the mildly toxic coral snake (Marevsová, Landová, & Frynta, 2009). Mimicry can therefore happen for different reasons. In the case of the poisonous deadly Coral snake, it acts as a mimic because it wants to appear less threatening. This will allow it to get closer to prey and therefore have greater access to food. In the case of the Milk snake, it wishes to appear more toxic than it is to scare off predators. Because of the alarming colors typically associated with danger and the appearance like the Coral snake, other organisms may mistake the harmless Milk snake for something more serious and therefore avoid it as it would a Coral snake (Marevsová, Landová, & Frynta, 2009).
I have chosen this relationship because I find it interesting that mimicry in this case tends towards the middle ground. It seems as though it is not beneficial to these organisms to appear extremely poisonous (as in the deadly Coral snake) or to be seen as completely harmless (as in the Milk snake) as both are mimicking the Coral snake. It also illustrates two of the reasons why mimicry can happen which is useful for evaluating organism relationships – we cannot always assume that we know the one reason why an organism is acting as a mimic. Finally, I find it interesting that although the actual colors used are the same, the banding patterns have evolved differently which suggests mimicry may be imperfect in these organisms but is evidently still effective.
- Harper Jr, G. R. (2006). Evolution of a snake mimicry complex. ProQuest.
- Marevsová, J., Landová, E., & Frynta, D. (2009). What makes some species of milk snakes more attractive to humans than others? Theory in Biosciences, 128(4), 227–235.