A Natural History of Rattlesnakes
I believe I mentioned back a ways that I received gift cards for Amazon and Barnes and Nobles for Christmas. One of the purchases I made was the book “RATTLER” by Chris Mattison. Mr Mattison holds several degrees in Zoology and is a Fellow of the Royal Photoghraphy Socity. He has written ten books and illustrated ten book on reptiles. He has also made six visits to the Americas to research the subject of snakes in particular the rattlesnake. This in effect will be a book review, and you kiddies get to be the teacher who issues my grade. If any one challanges our quoted facts we will stand together and point collectively with our grubby finger in the general direction of England and say in unison “He said”.
About thirty species of snakes have evolved a unique appendage on the end of their tails. All reside in America, but have close relatives in Asia without the rattle. The rattlesnake is special to biologist because they are considered the pentacle of snake evolution, considered by many to be the most up to date snake. There are 206 species of vipers, 130 pit vipers of which 30 are rattlesnakes. So let me begin.
I have stated much of this in the past but let me say those facts were gleaned from field guide books and facts picked of nature shows on television.
First is the Eastern Diamond Back Rattlesnake. Can reach six foot, the longest recorded measured eight foot. But the average length of a large one is four to five foot.
Second is the Western Diamond Back Rattler. Occasionally six foot eleven inches, but average three foot three inch.
Third is the Neotropical Rattler at six foot six inches average three foot three inch.
Other large members of the species are the Timber Rattler, Canebrake Rattler, Red Diamond Back and the Mojave Rattler at over The Three foot mark.
The smallest varieties are the members of the pygmy and Montane Rattlesnakes at around twenty inches.
The males of each species are usually larger than the females, except for the Sidewinder where the female out grows the male.
In North America the rattlesnake is more heavly bodied in proportion to length than other snakes. The females are generally thicker bodied than the male with a difference of about twenty percent. The Sidewinder is consistently heavyer (thicker) than the other species.
Size and Shape of the Head
Rattle snake heads are characteristally wide and spade shaped. The width of the head is necessary to accommodate the venom glands. There two genera or rattlesnakes, defined by the arraigments of their head scales, The Crotalus and the Sistrurus. The sistrurus are limited to three species of the Pygmy Rattlers including the Sidewinder. The Sidewinder also has a pair of raised scales above the eyes giving it a horned appearance.
Rattle snakes have relative short tails, all stout bodied snakes have stubby tails. Woah! how do you tell the tail from the rest of the body?? We will get to that when we talk about scales later. The snakes with the longer tails are the faster movers or the climbers, the rattler is neither of these.
Color and Pattern
Color and pattern are important to the rattle snake as it helps them to remain undetected while it rests, basks or lies in ambush while waiting for its prey. Many species of rattlers are similar to each other compounded by the fact many species occur in different colors. Because they rely on camouflage, snakes of a different species living in the same area my resemble each other. While wide ranging species may vary in coloration depending on the coloration of the area they live in. Male and female of a species will resemble each other in color.
The comon colors are earth tones browns, greys, yelowish-grey, greenish-grey and reddish-browns. there are no brighty colored rattle snakes.
Broadly speaking patterns can be divided into the diamond-backed, blotched spotted, banded and plain. the first two are the most common and in some species some are combined.
Rattle snakes are of course covered with scales, but not all scales on the snake are the same. Each scale is formed from a thickened part of the skin. This differs from the scales of a fish which are seprate from the skin and loosely attached and can be scraped off. The scales of the snake do not stretch but the skin between the scales can allowing it to swallow larger prey. Scales on rattlers head are small and granular in apparance. The Sisururas (the three pygmy rattlers) have nine larger plates between the eyes and snout this sets them apart from the rest and are easily recognised (if you allow it to get close enough, nuff said?). We could go on and discuss the different head scales but are you really that interested?
The scales on the back and sides they are pointed and have broad bases. The ones on the back are larger than the sides, both have a low ridge in the center which are called a keel. All rattlers have keeled scales. The scales on the underside or belly are called the Ventral scales. These scales reach all the way across the underside and are wider and have no keels. These scales serve as tread and help provide traction for locomotion. The scales of the tail are called subcaudal scales. They may be single or in pairs. Normally they are single toward the base of the tail. Males usually have more subcaudal scales than females because their tails are longer.
Next time I get the urge to sit and write I will carry on with a study of the rattles, venom, fangs (have a better understanding of their construction than before) and habits and habitats.
On closing for the night just saw on the news before coming in here Sweetwater Oklahoma or Texas was having its annual Rattlesnake roundup. They were expecting to gather up to 10,000 pounds of snakes in three days. They were dumping them in by the basket full into a enclosure they appeared to be in the two to three foot range. The roundup was started in the earlier days as a way to help control the snake population.
Well I have spouted so many facts that my old head is hurting. Guess I’ll rambel off somewhere and lay my grey hair down on something soft.