Galapagos Snakes

Category: Reptile
Family: Colubridae
Length: Up to 120cm (39 in)

Three species of snakes have been recorded in Galapagos (3 terrestrial indigenous residents, two of which are represented by 3 subspecies and the other by 2 subspecies). Endemic species include the Floreana Snake (which includes named subspecies Española Snake and San Cristobal Snake), the Galapagos Snake (which includes named subspecies Fernandina Snake and Isabela Snake), and Slevin's Snake (which includes named subspecies Steindachner's Snake).

FLOREANA / ESPANOLA / SAN CRISTOBAL SNAKE

Scientific Name: Philodryas biserialis
Length: Up to 120cm (39 in)

Locally fairly common. Three named subspecies occur, mainly in the arid and shore zones: Floreana Snake biserialis (Champion, Floreana and Gardner-near- Floreana), Española Snake hoodensis. (Española and Gardner-near- Española) and San Cristobal Snake eibli (San Cristobal). They feed by constricting their prey, although slightly venomous

Identification: Virtually impossible to identify unless examined in the hand, identification being confirmed on the basis of the shape, pattern and number of scales on certain parts of the body. However, this species only occurs on islands from which the two other species that occur in Galapagos are absent. As with the other species, predominantly brown with yellow stripes or dark grey with yellow spots on the upperside forming a zigzag pattern.

GALAPAGOS / FERNANDINA / ISABELA SNAKE

Scientific Name: Alsophis dorsalis
Length: Up to 120cm (39 in)

Locally fairly common. Two named subspecies occur, mainly in the arid and shore zones: Galapagos Snake dorsalis (Baltra, Rabida, Santa Cruz, Santa Fe and Santiago), Fernandina Snake occidentalis (Fernandina) and Isabela Snake helleri (Isabel a and Tortuga). Feeds by constricting its prey, although slightly venomous.

Identification: Virtually impossible to identify unless examined in the hand, identification being confirmed on the basis of the shape, pattern and number of scales on certain parts of the body. As in the other species, predominantly brown with yellow stripes or dark grey with yellow spots on their upperside forming a zigzag pattern. However, the present species only occurs on islands from which P. biserialis is absent, and although present on the same islands as A. slevini, that species is considerably smaller.


SLEVIN'S / STEINDACHNER'S SNAKE

Scientific Name: Alsophis slevini
Length: Up to 50 cm (19.7 in)

Locally fairly common. Two named subspecies occur, mainly in the arid and shore zones: Slevin's Snake slevini (Fernandina, Isabela and Pinzon) and Steindachner's Snake steindachneri. (Baltra, Rabida, Santa Cruz and Santiago). Feeds by constricting its prey, although slightly venomous.

Identification: Virtually impossible to identify unless examined in the hand, identification being confirmed on the basis of the shape, pattern and number of scales on certain parts of the body. As in the other species, predominantly brown with yellow stripes or dark grey with yellow spots on the upperside forming a zigzag pattern. However, the present species only occurs on islands from which P. biserialis is absent and although present on the same islands as A. dorsalis, that species is considerably larger.