A Natural History of the Gray-Banded King Snake Lampropeltis alterna (Serpentes: Colubridae)

A Natural History of the Gray-Banded King Snake Lampropeltis alterna (Serpentes: Colubridae) Jenny Hernandez, Miguel Quirch, and Ellis Nordyke Department of Biology, University of St. Thomas, Houston TX, 77006 Lampropeltis alterna (gray-banded king snake) was first discovered in the Davis Mountains of West Texas (Brown, 1901). It is a medium sized colubrid snake inhabiting the Trans-Pecos/Chihuahuan Desert regions of west Texas, southern New Mexico, and northern Mexico. L. alterna inhabits the dry hillsides, canyons, and mountain slopes of the northern Chihuahuan Desert along the Rio Grande, eastward into the Edwards Plateau, and westward into the mountains of the western Trans-Pecos. Although the potential habitat is much larger, L. alterna are currently found in 15 counties in Texas (Brewster, Crane, Culberson, Edwards, El Paso, Hudspeth, Jeff Davis, Kinney, Pacos, Presidio, Sutton, Terrell, Upton, and Val Verde), Eddy County in New Mexico, and in the Mexican states of Coahuila, Durango, and Nuevo Leon. Area-wise, this is a small range when compared to the range of most colubrid snakes. Two distinct color morphs have been described (Tanzer, 1970). L. alterna with wide red bands were called “blairi” morphs and those with little or no red marks and the presence of some alternating black bands as “alterna”. Background color in both morphs ranges from black to light gray. The “blairi” morph was described as a new species of king snake (Flury, 1950) but, upon finding “blairi” and “alterna” in the same litter, it was concluded L. alterna is represented by a single polymorphic species (Tanzer, 1970). The color and patterning of L. alterna is extremely variable throughout its range. There is great variation within populations and there are characteristic differences between populations. Over their limited range, small habitat isolated populations are often separated by geographic and environmental barriers with gene flow between isolated groups considered to be minimal (Tenant, 1998). Collector: Dan Johnson Collector: Chris Sheldon Black Gap, 6/10/1990 Collector: Chris Sheldon Black Gap, 5/21/1993 Collector: Mike Forstner Black Gap, 1990 Collector: Dan Johnson Black Gap, 6/12/1993 Collector: Dan Johnson Black Gap, 6/12/1993 Collector: Dan Johnson Hueco Mountains Collector: Gerold Merker Hueco Mountains Collector: Richard McNabb FM 674 Collector: Troy Hibbitts Sanderson - US 90 West, 1994 Collector: Marla Hibbitts Sanderson - US 90 West, 1995 Collector: Joe Forks Sanderson - US 90 West Collector: Ellis Nordyke Collector: Buzz Ross Pandale Dirt Collector: Buzz Ross Pandale Dirt

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Transcript of A Natural History of the Gray-Banded King Snake Lampropeltis alterna (Serpentes: Colubridae)

A Natural History of the Gray-Banded King Snake Lampropeltis alterna (Serpentes: Colubridae)

Jenny Hernandez, Miguel Quirch, and Ellis Nordyke

Department of Biology, University of St. Thomas, Houston TX, 77006

Lampropeltis alterna (gray-banded king snake) was first discovered in the Davis Mountains of West Texas(Brown, 1901). It is a medium sized colubrid snake inhabiting the Trans-Pecos/Chihuahuan Desert regions ofwest Texas, southern New Mexico, and northern Mexico. L. alterna inhabits the dry hillsides, canyons, andmountain slopes of the northern Chihuahuan Desert along the Rio Grande, eastward into the EdwardsPlateau, and westward into the mountains of the western Trans-Pecos. Although the potential habitat is muchlarger, L. alterna are currently found in 15 counties in Texas (Brewster, Crane, Culberson, Edwards, ElPaso, Hudspeth, Jeff Davis, Kinney, Pacos, Presidio, Sutton, Terrell, Upton, and Val Verde), Eddy County inNew Mexico, and in the Mexican states of Coahuila, Durango, and Nuevo Leon. Area-wise, this is a small rangewhen compared to the range of most colubrid snakes. Two distinct color morphs have been described(Tanzer, 1970). L. alterna with wide red bands were called “blairi” morphs and those with little or no redmarks and the presence of some alternating black bands as “alterna”. Background color in both morphsranges from black to light gray. The “blairi” morph was described as a new species of king snake (Flury, 1950)but, upon finding “blairi” and “alterna” in the same litter, it was concluded L. alterna is represented by a singlepolymorphic species (Tanzer, 1970). The color and patterning of L. alterna is extremely variable throughout itsrange. There is great variation within populations and there are characteristic differences betweenpopulations. Over their limited range, small habitat isolated populations are often separated by geographicand environmental barriers with gene flow between isolated groups considered to be minimal (Tenant, 1998).

Collector: Dan Johnson

Collector: Chris SheldonBlack Gap, 6/10/1990

Collector: Chris SheldonBlack Gap, 5/21/1993

Collector: Mike ForstnerBlack Gap, 1990

Collector: Dan JohnsonBlack Gap, 6/12/1993

Collector: Dan JohnsonHueco Mountains

Collector: Gerold MerkerHueco Mountains

Collector: Richard McNabb FM 674

Collector: Troy HibbittsSanderson - US 90 West, 1994

Collector: Marla HibbittsSanderson - US 90 West, 1995

Collector: Joe ForksSanderson - US 90 West

Collector: Ellis Nordyke