Thursday, May 24, 2012

Mating Black Snakes

Mort Shurtz sent me these pictures of mating black snakes in a tree. "About twenty feet from our deck my son Jay noticed two blacksnakes in some form of endearment in a maple tree."  Like any dedicated Master Naturalist, he ran for a camera and soon had "five voyeurs gawking at these two mating snakes."

The Western Rat Snake, Pantherophis obsoletus, known locally as the Black Rat Snake goes by many different common names across the country.  Its official common name (if there can be such) was recently changed to Texas Rat Snake although they are predominately north and east of Texas (see my recent diatribe).

Black Rat Snakes are one of the largest native snakes in North America, growing up to 8 feet long.  They are talented climbers of trees, rocks and seemingly any structure.  We watched a five foot specimen scale the exterior wall of our Bull Mills house and crawl into a fissure that we couldn't even see from below.  We had evicted it twice before because of its unsanitary habits, such as leaving shed skins in the closet and dropping white powdery excreta on the living room floor.

Although young snakes are vulnerable to a number of predators such as foxes, skunks and raccoons, the adults are most threatened by humans, victims of either tires or fear.  They respond to danger by shaking their tail and spreading a foul musk, and they will give you a non-toxic bite if you try to pick one up.

They are constrictors, progressively tightening coils around their prey with each exhalation until the victim is smothered.  Their prime prey are rodents although they will eat other small mammals, birds and their eggs.  Mort's snakes probably met on a dinner date, headed to the bird house seen in the video below.

Males wait for females in a territory which they defend from other males.  They find females by benefit of pheromones, mating for minutes to hours with the male sometimes holding on to the female with his mouth so she won't get away.  The female later produces 6-24 eggs from which the young will emerge.  One of the significant threats to their eggs is the burying beetle, (Nirtophorous pustulatus).  "The adult beetles lay their eggs in the snake eggs and the beetle larvae feed on the developing snake embryos."*

*  From Pennsylvania State University,  which has a detailed account of their reproduction.

More Black Rat Snake pictures and video are at this site
Various rat snake species information is at Animal Diversity Web  

1 comment:

  1. It's great to learn more about blacksnakes. Sometimes we overlook the regulars in the environment as not 'exotic' enough. Thanks.