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Nature Notes
by Bob Thomas

Some years ago, my phone rang, and a lady asked, “There is a snake in my tree, about 20 feet above the ground. Can you identify it?” I asked her to describe it and she said, “it is about four feet long, with dark blotches, has a bit of red edging on each light scale between the blotches, and the pupils are round.” I was surprised at the detail she shared, so I asked how she could see such small characteristics. She said, “Because I’m looking out of my second story window and it is on a branch just three feet away.”

She described a Texas rat snake (Pantherophis obsoletus linheimeri), the so-called chicken snake, an arboreal critter that can use its angular ventral scales to climb straight up the trunk of a tree.

This species is somewhat common in forested areas, but it seems to do quite well in parts of cities that have large trees. In fact, these snakes most commonly visit the ground at night, preferring to spend their days in the treetops.

Texas rat snakes are non-venomous, killing their prey by constriction. Adults prefer rats and mice, but will take birds and their eggs. Juveniles eat frogs, soft-bodied insects, and pinkies.

Their demeanor is rather aggressive. They defend themselves by striking, biting and smearing their foe with a foul smelling musk from their cloacal glands. When excited, they rapidly vibrate their tails.

Texas rat snakes are egg layers, and can produce up to 20 eggs. Eggs are laid in a moist place, and are left unattended by the female. They hatch in about two months, and produce juveniles that are each about 12 inches long. They are lighter in color than the adults, but equally aggressive.

This is one of Louisiana’s largest snakes, commonly reaching lengths over five feet. The largest specimen known to science, 86 inches in length, was found in an attic in Gretna in 1983 and subsequently released at the Louisiana Nature Center in eastern New Orleans.

Also published in Delta Journal, The Times Picayune, November 2, 2008.

                                        

Texas rat snake, Pantherophis obsoletus                                             Another typical pattern of adult Texas rat
linheimeri
, an adult with the characteristic                                          snakes. This snake is about to shed its
red on scales between the blotches.                                                   skin, so it is rather dull and the eyes are
Photo by Bob Thomas.                                                                   "opaque" (meaning there is a bluish fluid
                                                                                                       under the spectacle that loosens the old
                                                                                                       skin just before shedding).
                                                                                                       Photo by Bob Thomas.

                                              

Defensive posture of a Texas rat snake.                                              Juvenile pattern of the Texas rat snake.
Note the readiness to strike, white interior                                          Photo by James Beck.
of the mouth, and the glottis (opening to
the respiratory system).
Photo by James Beck.

                                            

Head of an adult Texas rat snake with                                            Record Texas rat snake - 86 inches long.
tongue protruded.                                                                        Note the amount of snake tail on the
Photo by Bob Thomas.                                                                ground; holder is 76 inches tall.