Desert Thrasher Working Group
The Desert Thrasher Working Group (DTWG) was formed in January 2010, following enthusiasm generated from a LeConte’s Thrasher Workshop held at the Barry M. Goldwater Range in Southwest AZ. During this workshop, concerns were raised about negative population trends in LeConte’s Thrashers, and concerns were mirrored for Bendire’s Thrashers. Loggerhead Shrikes also exhibit significant population declines, and in desert habitats are largely overlapping with these two thrasher species. All three species have showed significant population declines based on BBS data, and are listed as species of conservation concern by the USFWS and Partners in Flight (PIF). In fact, PIF considers these two thrasher species among species requiring the most urgent action. Similarly, within their respective ranges, each state lists them as a Species of Greatest Conservation Need. Conservation action is needed to improve the status of these species. However, research gaps (e.g. true population size and trends, habitat needs, movement patterns, limiting factors) are significant, and mechanisms to achieve meaningful conservation measures are not well understood or defined.
The DTWG identified the need to better understand these understudied birds, with the goal of developing management recommendations to address their long-term declines. In 2015, the group facilitated the design and implementation of a research project on breeding Bendire’s Thrashers in New Mexico. The effort was expanded into Arizona in 2016 to conduct statewide surveys with the assistance of more than 50 volunteers under the support and guidance of Tucson Audubon Society and Arizona Game and Fish Department. In 2017 with funding from the Bureau of Land Management (BLM), the group collaborated to design and implement a pilot year effort to survey for Bendire’s Thrashers, LeConte’s Thrasher, and Loggerhead Shrike in Arizona, California and Nevada. With additional BLM funding, the group expanded the study throughout Arizona, California, Nevada, New Mexico and Utah in 2018. The DTWG has implemented surveys across most of the species range in the U.S., and has plans to expand efforts into Mexico.
The Desert Thrasher Working Group seeks to design, implement, and evaluate range-wide, collaborative research and monitoring efforts that will increase our knowledge and understanding of at-risk desert species in order to proactively inform conservation and management strategies.
Goals and Objectives
The primary objective of the current study is to estimate distribution, determine population trends over time, and to identify habitat preferences for Bendire’s Thrasher, LeConte’s Thrasher, and Loggerhead Shrike. Our long-term goal is to develop a series of Best Management Practices that will inform effective conservation management strategies.
The group consists of a diverse partnership of federal, state, and non-governmental organizations including: Arizona Game and Fish Department, Bureau of Land Management, US Fish and Wildlife Service, Sonoran Joint Venture, Point Blue Conservation Science, Department of Defense, Great Basin Bird Observatory, Tucson Audubon Society, Audubon Arizona, Sonoran Audubon Society, Audubon New Mexico, New Mexico State University, New Mexico Department of Game and Fish, and Utah Division of Wildlife Resources.
- Blackman, S. T. and J. Diamond. 2015. Meta-population dynamics of Le Conte’s Thrasher (Toxostoma lecontei): a species at risk on three southwestern military installations. Year 3 report. Wildlife Contracts Branch, Arizona Game and Fish Department.
- Desmond, Martha J. and Cody Bear Sutton. 2017. Breeding Habitat Requirements and Territory Size of Bendire’s Thrasher (Toxostoma lecontei). Department of Fish, Wildlife and Conservation Ecology, New Mexico State University. Final Report to New Mexico Department of Game & Fish.
- Kondrat-Smith, Christina and Shawn Lowery, 2018. Movement Patterns, Survivorship, and Home Range Size of LeConte’s Thrasher (Toxostoma lecontei) on the Barry M. Goldwater Range. Poster. Arizona Game and Fish Department.
- Great Basin Bird Observatory. 2019. Region-Wide Desert Thrasher Monitoring, 2017-2018: Comprehensive Report. Submitted to Bureau of Land Management.
- Sheppard, J.M. 1970. A study of the Le Conte’s Thrasher. California Birds 1:85-95.
- Sheppard, J. M. 2018. The Biology of a Desert Apparition: LeConte’s Thrasher (Toxostoma lecontei). Studies of Western Birds no. 2. Western Field Ornithologists.