Monday, June 24, 2013

Shedding Snakes

Like a fish picture, it probably isn't that long.
We commonly find snake skin sheds in and around our Bull Creek house, usually contributed by the resident black rat snakes.  These are dry and crinkly like tissue paper and are frequently chewed up in fragments.  This week was different.

Shed wrapped around the foundation
Barb was behind the house when she saw a black rat snake snuggled in close to the foundation at the corner.  It was in the act of shedding and it wiggled through an impossibly small hole in the well house wall to escape, undoubtedly embarrassed by its state of undress.

The skin was remarkable when fresh, more like the consistency of damp Saran Wrap.  All the external features of the snake were preserved including the eyes and nostrils.

The process of moulting includes the shedding of skin by amphibians, reptiles or the exoskeleton by insects and arachnids.  The exercise requires energy and leaves the animal vulnerable to predators but is necessary for the animal to grow into a larger covering.

The snake starts the process of moulting by rubbing the tight skin against a hard object until it splits.  The first rents commonly occur around the lips.  It generally sheds its skin in one continuous piece, peeling it off inside out like removing a sock.  This leaves all the features including their ocular scale (called a brille), a snake's version of our cornea, attached. 

Shed with the old ocular scale intact
A few days prior to shedding, a snake's vision is impaired, possibly to the point of blindness.  A layer of air separates the old and newly developed  layers of scale, clouding its vision.  Snakes tend to hide and not hunt during this pre-moulting period.

Barb saw the snake the next day and said it wasn't as long as we had thought.  She was right again.  The nearly transparent shed had folds from the overlapping scales, and when stretched out as it is peeled off, it is about a third longer than the snake itself.  Rattlesnakes are the exception as the shed ends at the rattle and the remaining skin adds thickness and segments to the hard rattles.

Left to nature (or in our closet) the skin is chewed by insects, moths and probably rodents as animals and plants leave little to be wasted in nature.  Humans seem to be a striking exception to this rule.

Life is short but snakes are long has information on identifying snakes by their sheds.

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