SAN FRANCISCO GARTER SNAKE Thamnophis sirtalis tetra taenia (Cope) 



Order: SQUAMATA Family: COLUBRIDAE 



Distinguishing characteristics : One of the most beautiful serpents in North America; 

 dorsal scales keeled; wide dorsal stripe of greenish yellow edged with black, bordered 

 on each side by a broad red stripe followed by a black one; belly greenish blue; top of 

 head red. 



Present distribution : Scattered colonies in the vicinity of reservoirs in the San 

 Francisco area. 



Former distribution : Western part of San Francisco peninsula from about San Francisco 

 County line south along crest of hills, at least to Crystal Lake and along coast to 

 Point Ano Nuevo, San Mateo County, California. 



Status : Very scarce and in peril. Listed as endangered by California Dept. of Fish & Game. 



Estimated numbers : Probably no more than a few hundred (Bruce Bury, pers . comm. , 

 1972). 



Breeding rate in the wild : Probably once a year. Broods of large size. 



Reasons for decline : Housing developments and control of waterflow entailing removal 

 of vegetation, both of which destroy habitat. 



Protective measures already taken : Fully protected in California as an endangered 

 species . 



Measures proposed : Retain bordering and emergent vegetation in reservoir areas . 

 Tules and other growth should be allowed to persist in brackish and fresh-water inlet 

 areas bordering on the sea. Such growth occurs in and around the Sharp Park Golf 

 Linds, where they may still occur. A refuge is suggested for the Crystal Lake region. 



Number in captivity : Few . 



Breeding potential in captivity : California biologists have one pair and the young have 

 been released back to native areas. 



Remarks : Submitted by Robert Stebbins . 



References : 



Bury, R. B. 1972. Status Report on California's threatened amphibians and 



reptiles. Calif. Inland Fisheries Adm . Report No. 72-2. 

 Fox, W. 1951. The status of the gartersnake, Thamnophis sirtalis tetrataenia . 



Copeia, 1951(4): 257-267. 

 Leach, H. R. and L. D. Fisk. 1972. At the crossroads — a report on California's 



endangered and rare fish and wildlife. California Dept. of Fish and Game. 

 Wright, A. H. and A. A. Wright. 1957. Handbook of snakes of the United States 



and Canada. Comstock Publishing Associates, Ithaca, N.Y. 



97 



