black rat snake title.gif (10265 bytes)

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blackrat1.jpg (140393 bytes)   Ouachita Parish, La.  Photo: Mike Monlezun

blackrat2.jpg (93675 bytes)    Ouachita Parish, La.  Photo: Mike Monlezun

Common name: Black rat snake
Generic name: Elaphe obsoleta obsoleta (Say)
Adult length: 42 - 72 inches.
Complete range: Southwest New England and s. Ontario to Georgia in the east; and sw. Wisconsin to Oklahoma and n. Louisiana in the midwest.
see RANGE MAP for range in Louisiana

The black rat snake is very common in many areas.  As with many of the Elaphe obsoleta species, the black rat snakes undergo changes in color and pattern.  In the case of the black rat snake, they are born a grayish color with dark blotches dorsally.  By the time they are around 3 feet long, they are near their adult coloration. Adult coloration ranges from jet black to a deep chestnut brown. One easy distinguishing feature on these snakes is the ivory white chin and throat.

In Louisiana, black rat snakes are found in the very northern part of the state.   There is a wide range in central to north-central Louisiana where intergrades are found.  In this area most of what is found phenotypically looks like dark Texas rat snakes, Elaphe obsoleta lindheimeri.

Black rat snakes are found in a variety of settings including farm areas, upland wooded areas, swampy areas, and near human habitation.  The well patterned young are often mistaken for other snakes, including pygmy rattlesnakes.  At a store Mike was working during the summer of 1998 in Monroe, an employee was telling me about a ground rattler that was just killed in the store.  Upon inspection ofthe snake a few minutes later, a dead yearling-sized black rat snake was found coiled around a mouse!!!

It would be very difficult to accurately estimate how beneficial rat snakes can be as far as quantities of rodents they would consume in the wild, but if the large quantities of mice eaten in captivity are any indication, it would be in our best interest to leave these non-venomous snakes alone.


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State Checklist | Herping in LA | Links | Authors | State Maps