Its Snake Week on iNaturalist! May 15 - May 21, 2016


This week the Critter Calendar focuses on a group of animals that usually provoke strong emotions in people - Snakes!

Comprising about 3,000 species, Snakes (suborder Serpentes) are squamate reptiles that lack limbs, eyelids, and external ears. All snakes have skin covered in scales, elongated bodies, and they are all carnivorous. It is believed they evolved from burrowing lizards around 100 million years ago, although the fossil record is spotty. Primitive extant snakes, like pythons and boas, have vestigial hind limbs known as anal spurs on either side of their cloaca, and thread snakes have vestigial pelvic girdles inside their bodies.


Snakes live in all types of habitats and on every continent on Earth (aside from Antarctica), and are most active in warm weather, as they are ectothermic, or cold-blooded. They can often be found basking on roads or trails, and find refuge in rocky outcrops or under cover. While most snakes are not harmful to humans, about 600 are venomous, 200 of which are considered to have venom which is medically significant. Make sure to watch where you put your hands and feet, especially around rocky areas.

Many snakes can be identified by color and pattern, but for some families like garter snakes, photographs of the head scales are necessary, so if you can safely get photos of the head, it’ll be very helpful on iNat.

Some notable snake families are:

Colubrids (Colubridae) - a bit of a catch-all group, nearly two thirds of all snake species belong to this family, including kingsnakes, cat-eyed snakes, and mole snakes. Most colubrids are not dangerous to humans, and either swallow their prey alive or constrict them. The bite of a boomslang, however, can be fatal. Interestingly, one of the world’s only poisonous (as opposed to venomous) snakes is the tiger keelback, which eats toads and sequesters the poison in two glands in its throat.


Elapids (Elapidae) - the cobras and sea snakes (although some list the sea snakes as separate). These highly venomous snakes have fixed front fangs and produce neurotoxic venom and generally lack the “triangle” shaped head of vipers. Cobras, coral snakes, and kraits are all members of the elapid family, and some, like the black mamba and coastal taipan, are considered the most dangerous snakes in the world.

Vipers (Viperidae) - these stocky venomous snakes have hinged fangs which spring forward when the snake bites. Their venom is mainly hemotoxic as opposed to neurotoxic. Usually ambush predators, many vipers have thermoreceptive “pits” between their nostrils and lips which allows them to “see” heat. Rattlesnakes, adders, and fer-de-lances are all members of of the viper family.


We’ll be keeping track of all your snake observations here. Happy serpent hunting and be careful out there!

Posted by loarie loarie, May 19, 2016 08:22

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Why did they stop the creature calendar?

Posted by ponderosa about 4 years ago (Flag)

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