Alameda whipsnake (=striped racer)
FWS Focus

Overview

Adults reach a length of 3 to 4 feet (91 to 122 centimeters). Their back is colored sooty black or dark brown with a distinct yellow-orange stripe down each side. The front part of their underside is orange-rufous colored. The midsection is cream colored. The rear section and tail are pinkish.

Characteristics
Overview

The Alameda whipsnake is a slender, fast moving, snake with a narrow neck, a relatively broad head and large eyes. The snake’s back is a sooty black color with a distinct yellow-orange stripe running down each side. It is an active daytime predator that holds its head high off the ground to peer over grass or rocks looking for potential prey.

It was listed as a threatened species on December 5, 1997. At the time of listing, the Alameda whipsnake was known to inhabit the inner Coast Ranges in western and central Contra Costa and Alameda counties. Since that time, the species is now known to occur in five populations throughout Contra Costa County, most of Alameda County, and small portions of northern Santa Clara and western San Joaquin counties.

Department of the Interior, Fish and Wildlife Service. 2020. Five-Year Review: Alameda Whipsnake (Masticophis lateralis euryxanthus) July 8. Available online at: https://ecos.fws.gov/docs/tess/species_nonpublish/2989.pdf

Scientific Name

Masticophis lateralis euryxanthus
Common Name
Alameda whipsnake (=striped racer)
FWS Category
Reptiles

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Habitat

Characteristics
Habitat

Alameda whipsnakes live in the California inner Coast Range. This area consists of mixed chaparral, coastal scrub, annual grassland with rock piles and oak woodland habitats. Rock piles are an important habitat feature for Alameda whipsnakes because they provide the snake with coverage from predators and are also home to the snake’s favorite food – lizards. 

Department of the Interior, Fish and Wildlife Services. 2020. Five-Year Review: Alameda Whipsnake (Masticophis lateralis euryxanthus) July 8. Available online at: https://ecos.fws.gov/docs/tess/species_nonpublish/2989.pdf

Grassland

Ecosystem with large, flat areas of grasses.

Coastal
Rural
Characteristic category

Food

Characteristics
Food

Alameda whipsnakes are great hunters and opportunistic eaters. The snake is an active daytime predator. It holds its head high off the ground to peer over grass or rocks looking for potential prey. The Alameda whipsnake’s favorite food is lizard, especially the western fence lizard. It also eats frogs, western skinks, alligator lizards, other snakes, small birds, amphibians, single-slender salamanders, small mammals and insects.

Department of the Interior, Fish and Wildlife Service. 2020. Five-Year Review: Alameda Whipsnake (Masticophis lateralis euryxanthus) July 8. Available online at: https://ecos.fws.gov/docs/tess/species_nonpublish/2989.pdf

Characteristic category

Behavior

Characteristics
Behavior

The Alameda whipsnake is an active, daytime hunter. When hunting, the snake moves with its head held high and occasionally moves it from side-to-side to peer over grass or rocks for potential prey. They are also good climbers that can escape into scrub or trees. Alameda whipsnake seek shelter in rock piles or in small mammal burrows and hibernates from November through February.

Threats to the species:

  • Loss and fragmentation of habitat due to urbanization and water storage development
  • Fire suppression efforts that result in the build-up of fuels creating conditions for hotter wildfires
  • Invasive species that eat the snakes such as rats, feral pigs and feral cats and dogs
  • Overgrazing, which significantly reduces or eliminates shrub and grass cover, potentially eliminating the snakes’ cover from predators

Department of the Interior, Fish and Wildlife Service. 2020. Five-Year Review: Alameda Whipsnake (Masticophis lateralis euryxanthus) July 8. Available online at: https://ecos.fws.gov/docs/tess/species_nonpublish/2989.pdf

Characteristic category

Lifecycle

Characteristics
Reproduction

The snake mates from March through June. Females typically lay six to 11 eggs per clutch. Eggs require about three months of incubation before hatching. The young appear in the late summer and fall. Parents have little involvement with their offspring after the eggs hatch.

Department of the Interior, Fish and Wildlife Service. 2020. Five-Year Review: Alameda Whipsnake (Masticophis lateralis euryxanthus) July 8. Available online at: https://ecos.fws.gov/docs/tess/species_nonpublish/2989.pdf

Characteristic category

Physical Characteristics

Characteristics
Color & Pattern

The Alameda whipsnake's back is a sooty black or dark brown, and they have a distinct yellow-orange stripe down each side. The front part of their underside is orange-rufous colored. The midsection of the underside is cream colored. The underside of the rear section and tail are pinkish.

Size & Shape

The Alameda whipsnake is a slender, fast-moving snake with a broad head, large eyes and slender neck.

MeasurementsLength: Adults reach a length of 24 to 36 inches (91 to 122 centimeters)

Characteristic category

Similar Species

Characteristics
Similar Species

Chaparral whipsnake

 

Geography

Characteristics
Range

The species is known to occur in five populations throughout Contra Costa County, most of Alameda County, and small portions of northern Santa Clara and western San Joaquin counties.

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Timeline

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