Snakes (suborder Serpentes) are elongated, limbless, flexible reptiles. There are about 2,900 species of snakes. Of these, 375 are venomous.
Size: Snake size varies to extremes by species. At up to 30 feet long, the reticulated python is the longest snake. At a minuscule 4 inches, the Barbados thread snake is the smallest.
Weight: The green anaconda isn’t the longest snake, but it is the heaviest – they can grow up to 550 pounds!
Lifespan: In captivity, some species will live as long as 50 years. Snake lifespan in the wild is more difficult to determine.
Snakes consume a variety of items including termites, rodents, birds, frogs, small deer and other reptiles. Snakes eat their prey whole and are able to consume prey three times larger than the diameter of their head because their lower jaw can separate from the upper jaw. To keep prey from escaping, snakes have rear-facing teeth that hold their prey in their mouths.
Venomous snakes inject their prey with venom, while constrictors squeeze their prey. They do not need to hunt everyday. Anacondas and pythons can survive for up to a year without food after feeding. Snakes hunt mostly at night.
Snakes are found throughout the world except Antarctica, Iceland, Ireland, Greenland and New Zealand. Most snakes are found in tropical regions. Snakes are found in many habitats including in the water, forests, deserts and prairies.
Often observed flicking its tongue, snakes use their forked tongue to smell the air. Snakes are ectotherms, meaning they must regulate their body temperature externally by sunning themselves or retreating to cool, shaded areas. Snakes hibernate during the winter. Snakes must shed their skin three to six times per year.
Most snake species lay eggs, but some species give birth to live young. Snakes lay their eggs in a warm location. With the exception of some python species, eggs and young are not cared for by the male or female.
Roads and habitat destruction are two of the main threats faced by snake species.
- Endangered Species Act (ESA): Four species of snake are classified as endangered under the Endangered Species Act; ten are classifed as threatened, seven are a candidate for listing, and over forty species are listed as a species of concern.
- IUCN Red List: Six snake species are currently listed as critically endangered, twenty-seven as endangered, forty as vulnerable, and twenty-four as near threatened. Two are listed a extinct.