Beyond Red and Yellow — Coral Snake Identification for Nerds

Transcript

Have you noticed how often people post pictures asking for identification of a snake that they're holding in their hands, and how often the snake that they're holding is a coral snake?

Misidentifying one and picking one up can be dangerous. Aside from sea snakes, coral snakes are the only elapids in the Americas. So they're the same family as things like cobras and mambas.

Their venom is pretty toxic. Their bites can be treated, but being treated for a coral snake bite is no fun. It's not something you want to go through.

By now, you have already learned or should have learned that the old red on yellow rule you might have learned as a scout or something is not a reliable way to identify coral snakes. And it's not just unreliable because people remember it incorrectly all the time. It's unreliable because there are too many exceptions.

There are harmless mimics that have color sequences that are close enough to coral snakes to be confusing. And there are sometimes real coral snakes that have atypical patterns, patterns that are not what you expect.

For example, Texas coral snakes are prone to a trait called melanism, where black pigment darkens the red and sometimes the yellow pigment to the point that they don't even look like coral snakes.

There are also albino coral snakes that are missing black pigment altogether.

Then in Latin America, all bets are off. Coral snakes there still tend to have red and black and either white or yellow bands, but they can be in just about any order. So from Mexico all the way to Argentina, the rule just doesn't apply at all.

Okay, the rhyme has been discussed to death. I'm not here to go over it one more time. If you just want to be safe, that's easy. Just don't pick them up.

So you've heard that the simple rules aren't reliable and the reliable rules aren't simple. So what are these features that you can look for that are reliable but not simple? Here are a couple of things you can look for.

First, look at their eyes. Coral snakes have very dark eyes, so dark that except under the brightest light, you can't even see their pupil. They just look like a solid black eye.

In most species, their eye sits within a black mask, so it can actually be difficult to even see their eye at a distance.

Coral snakes also have very small eyes, while the mimics have very large eyes in which the pupil is very clearly visible. So that's a detail you can look for.

Next, look between the eye and the nostril. In harmless mimics, there's a scale in that space called the loreal scale. Elapids like coral snakes don't have that. Their preocular scale, the scale right in front of their eye, comes forward and meets the nasal scale. So they don't have that.

That reliably differentiates coral snakes from their mimics.

Obviously, these are not things you can examine from six feet away or when a snake is moving. And coral snakes are nervous, twitchy snakes. They never hold still. And getting close to them means you have to be very careful.

So what's the point of all this? The point is that there's rarely one simple rule for identifying any snake. You have to look at multiple factors, details of their anatomy, their color pattern, their head shape, their geography, where they're located.

So curiosity is great. Confidence is great. But overconfidence with a potentially dangerous animal is how you end up in the ER.

So if you can't identify something with 100% certainty, don't pick it up.