Giant Garter Snake

Thamnophis gigas

Biology and ecology 3

The giant garter snake is endemic to the Central Valley wetlands of California. It is active when water temperatures are at 20°C or more, and is dormant underground when its aquatic habitat is below this temperature. Fish and frogs form a large portion of the diet of the giant garter snake.

Destruction of wetland and habitat has been so widespread, this species is listed as threatened by the state and federal governments. The giant garter snake populations of the San Joaquin Valley are now tiny disconnected remnants. It has been extirpated from 98% of the former San Joaquin habitat. The giant garter snake has fared better in the Sacramento Valley because rice cultivation and the associated canals have provided habitat, when rice land is fallowed, populations seem to then move away from adjacent ditches.

In addition to habitat loss and fragmentation, introduced predators such as the American bullfrog may also be suppressing recovery. Attempts are underway to restore artificial wetlands to provide quality habitat for the giant garter snake, but it is too early to know if these efforts will significantly aid the recovery of this threatened species.

Conservation biology 3

Destruction of wetland and habitat has been so widespread, this species is listed as threatened by the state and federal governments. The giant garter snake populations of the San Joaquin Valley are now tiny disconnected remnants. It has been extirpated from 98% of the former San Joaquin habitat. The giant garter snake has fared better in the Sacramento Valley because rice cultivation and the associated canals have provided habitat, when rice land is fallowed, populations seem to then move away from adjacent ditches.

In addition to habitat loss and fragmentation, introduced predators such as the American bullfrog may also be suppressing recovery. Attempts are underway to restore artificial wetlands to provide quality habitat for the giant garter snake, but it is too early to know if these efforts will significantly aid the recovery of this threatened species.

Sources and Credits

  1. (c) Yolodave, some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Giant_Garter_Snake_1.jpg
  2. (c) 2011 Bill Stagnaro, some rights reserved (CC BY-SA), http://calphotos.berkeley.edu/cgi/img_query?seq_num=379188&one=T
  3. (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Giant_garter_snake

More Info

Range Map

iNat Map

Region Central Valley