The Daily Bucket is a regular series from the Backyard Science group. Here we talk about Mother Nature in all her glory, especially the parts that live nearby. So let us know (as close as you are comfortable) where you are and what's going on around you. What's the weather like? Seen any interesting plants, bugs or critters? Are there birds at your feeders? Deer, foxes or peahens in your yard? Seen any cool rocks or geological features? Post your observations and notes here. And photos. We like lots of photos. :)
It has the most potent venom of any animal in North America. It is spectacularly colored, with bright red, yellow and black bands. It is lots more common than many people think. Yet few people in Florida have ever actually seen a Coral Snake.
Eastern Coral Snake, Micrurus fulvius.
The Elapids are a large family of tropical snakes, containing about 325 species. They are distinguished from other snake groups by having short fixed fangs at the front of their mouth, through which they inject a venom that is largely neurotoxic and acts to paralyze their prey and kill it through suffocation. The best-known members of the family are the cobras, but kraits, sea snakes, mambas, and taipans are also Elapids. In most areas of the world, the Elapid species are outnumbered by the Vipers; Australia is unusual in having a larger number of Elapids. In Europe, there are no native Elapids at all.
The Coral Snakes are a fairly large group within the Elapids. There are 16 different species of Coral Snakes in southern and southeast Asia, and 65 species in North and South America. DNA study has shown that they evolved first in the area of southeast Asia and spread from there.
In the New World, Coral Snakes are mostly a tropical group, ranging through Central and South America. In the United States, we have just two species. The small Arizona Coral Snake, found in the southwest, is classed as Micruroides euryxanthus. The larger Eastern Coral Snake, found in the southeast, is Micrurus fulvius (but some authorities now advocate placing the Texas Coral Snake as its own species, Micrurus tener). Because of its bright color bands, it is also sometimes called the Candy-Cane Snake or the Harlequin Snake.
The longest length ever recorded for an Eastern Coral Snake was just shy of 48 inches, but the vast majority of individuals barely reach half that length. They are secretive snakes, preferring habitats with dry well-drained soil, like pinelands, where they spend all their time buried in leaf litter, hidden in burrows, or underneath rocks or logs. This is where they catch their prey of small lizards (skinks and small Glass Lizards being a favorite) or other snakes (Crowned Snakes are a favorite, but Coral Snakes have also been known to eat smaller Coral Snakes). Because they are little-studied, not much is known about the size of their populations, but they do not appear to be rare--though most people only encounter them if they accidentally uncover one by digging in their garden, raking leaves, or rolling over a log. They occasionally turn up at construction sites, and sometimes heavy rains can drive them out from their shelters. They seem to do most of their hunting just after dawn.
Because it is related to the cobras and has, drop for drop, the most potent venom of any North American snake, the Coral Snake has a fearsome reputation. The venom works by interfering with nerve transmission, killing the victim by paralyzing the muscles that power breathing. Often, no symptoms appear until several hours after the bite, when it is already too late.
The Coral Snake is, however, a very shy animal, and usually does not even try to bite unless it is actually handled or stepped on. When threatened, Coral Snakes will often curl the tip of their tail and raise it up so it looks like a head, to fool an attacker. The fangs are very short and the mouth cannot open very wide, so it's difficult for the snake to get in a good bite--and then it must chew the venom into its victim. The lethal dose in humans is estimated to be around 5 mg, but many of the smaller snakes can't even produce that much. Nevertheless, Coral Snakes are potentially lethal, and about one in five untreated bites have been fatal. (Since 1967, a commercial antivenom has been produced for Coral Snake bits, though production was stopped in 2010 because there weren't enough bites every year to need it.)
There are two look-alikes in Florida that mimic the coloration of the Coral Snake to gain protection from predators--the Scarlet Snake and the Scarlet King Snake. To tell them apart, Floridians often learn a little ditty: "Red touch yellow, kill a fellow; red touch black, venom lack". The mimics also have red noses; coral snakes have black noses. (The Florida Keys Coral Snake populations often lack any yellow rings.) But the best plan is just to not mess with any snake.
Not much is known about the Coral Snake's lifestyle. The eggs are laid in clutches of six or seven in the spring, and hatch out in the summer into seven-inch youngsters that are capable of taking care of themselves from birth. The snakes apparently grow quickly, with captives reaching 18 inches in just two years. In captivity they have lived over seven years. In the wild, Coral Snakes are eaten by King Snakes (who are immune to the venom), and also by birds of prey.
And now it is your turn. Let us know what's going on in your neck of the woods. :)