Ecology of a Population of the Narrow-Headed Garter Snake (Thamnophis rufipunctatus) in New Mexico: Catastrophic Decline of a River Specialist

• Published in: The Southwestern naturalist Vol. 54; no. 4; pp. 461 - 467
• Main Authors: Hibbitts, Toby J, Painter, Charles W, Holycross, Andrew T
• Format: Journal Article
• Language: English
• Published: Department of Biology, Box 1651, Edwardsville, IL 62026 The Southwestern Association of Naturalists Southern Illinois University Edwardsville 01.12.2009; Southwestern Association of Naturalists
• Subjects: Animal behavior; Animal traps; Birds; Diets; Environmental aspects; Feature s; Freshwater; Freshwater fishes; Gambusia affinis; Garter snakes; Garters; Habitats; Hot springs; Natural history; Opportunistic behavior; Population ecology; Population estimates; Population size; Riverbeds; Rivers; Sampling; Snakes; Studies; Tails; Thamnophis rufipunctatus; Traps; New Mexico; USA, New Mexico; USA, California, San Francisco
• ISSN: 0038-4909; 1943-6262
• DOI: 10.1894/GC-195.1

We studied natural history and ecology of Thamnophis rufipunctatus at San Francisco Hot Springs, Catron County, New Mexico. Gee minnow traps were more effective at sampling adults than opportunistic captures. Females were larger than males in snout–vent length and mass, but males had longer tails. Although females were larger, rates of growth for juvenile males and females were similar. In 1996, the population was ca. 7.2 adult snakes/ha; however, we did not detect snakes in subsequent visits. Thamnophis rufipunctatus was most likely to be captured at sites with steep riverbed slope and large rocks of uniform size. Diet was exclusively fish, of which a large proportion was the introduced Gambusia affinis. This population of T. rufipunctatus was one of the most robust in the United States and it has completely disappeared in <10 years.