Cooperative Fish and Wildlife Research Units Program: Arizona
Education, Research and Technical Assistance for Managing Our Natural Resources

Arizona Project

Population ecology of narrow-headed gartersnakes

July 2021 - May 2025


Participating Agencies

  • U.S. Fish and Wildlife Service

The narrow-headed gartersnake (Thamnophis rufipunctatus, hereafter THRU) is a federally threatened species endemic to the Mogollon Rim of central Arizona and western New Mexico. This species has undergone marked declines throughout its range due primarily to introduced fish and crayfish and loss or degradation of riparian and within-stream habitat. There is currently no THRU species recovery plan and in 2020 the U.S. Fish and Wildlife Service formally began the most recent Species Status Assessment (SSA) for THRU, which is anticipated to form the basis for the species recovery plan. However, there is relatively little empirical data available on the movement ecology and population dynamics of THRU, which span multiple seasons. This lack of critical information on how snakes seasonally shift activity and habitat use is currently an impediment to conservation managers to more accurately assessing range-wide and site-specific population risk and implement management actions. Additionally, a lack of empirical demographic parameter estimates (e.g., survival) inhibits efforts to conduct population viability analyses. This information would allow managers to identify at-risk populations and direct site-specific management actions, thereby aiding in species recovery.

This proposed study will address ecological and geographic gaps in the knowledge of THRU by studying the spatial, habitat, and population ecology of THRU along Canyon Creek in central Arizona. The results of this proposed study, when combined with previous studies on THRU, will help us better understand the geographic variation in THRU ecology and increase confidence in management recommendations and status assessments.

The goals of this study are to: (1) conduct three summers of mark-recapture sampling to estimate survival and abundance; and (2) develop and test implantation and field tracking protocols using harmonic transponder tags using a closely related species, the western terrestrial gartersnake, and, conditional upon success of these efforts, implant harmonic transponder tags into juvenile and adult THRU at Canyon Creek to monitor space use and habitat selection.

Presentations Presentation Date
Schafer, J.N., W.L. Heuring, T.R. Harris, R.A. Allard, M.J. Ryan, T. Roderick, J. Bauder, and D. Wood. 2023. Developing a breeding and reintroduction program for the threatened narrow-headed gartersnake. Joint Annual Meeting of the Arizona-New Mexico Chapter of the American Fisheries Society and the Arizona and New Mexico Chapters of The Wildlife Society, Farmington, New Mexico. February 2023
Mohebbi, R., T. Roderick, M. Bogan, and J. Bauder. 2024. How do trap contents impact the capture rates of narrow-headed and western terrestrial gartersnakes at Canyon Creek, AZ? Joint Annual Meeting of the Arizona-New Mexico Chapter of the American Fisheries Society and the Arizona and New Mexico Chapters of The Wildlife Society, Flagstaff, Arizona. February 2024