Carrizo Plain Le Conte's Thrasher


Le Conte’s Thrasher

(San Joaquin population) (Toxostoma lecontei) is a Bureau of Land Management sensitive species as well as a California species of special concern . Its historical range was from southern Fresno County to the Transverse Ranges in Kern County, west through the Cuyama Valley (San Luis Obispo County). It is now found only in the Maricopa-McKittrick area, the Carrizo Plain, and possibly the Lost Hills area. The Carrizo Plain National Monument is one of the largest intact parcels of habitat in the thrasher’s current range. Current bird monitoring methods and programs do not adequately address censusing and tracking this secretive species, or its present exact distribution and habitat associations. It is a resident, non-migratory species; therefore, the factors that drive its population are local. Habitat loss due to energy development, agriculture, and wildfire may be the largest inhibitors of population growth and habitat reoccupation as Le Conte’s Thrashers in the San Joaquin Valley depend on the presence of saltbush (Atriplex species) and do not tolerate high levels of human disturbance. common Saltbush8


Locally this project will establish a baseline population index of the San Joaquin population of Le Conte’s thrashers as well as a songbird inventory of breeding birds within the Carrizo Plain National Monument. This baseline information will assist in the long-term monitoring of population and species changes in suitable habitat and changes in distribution inside the National Monument. The information acquired regarding habitat associations and human disturbance factors in the National Monument can also serve to guide BLM in developing energy elsewhere on the San Joaquin Valley floor and other areas adjacent to the Monument.

Final Report to the BLM

Download the reports to the Bureau of Land Management presenting our findings from the field season surveys conducted within the Carrizo Plain National Monument.

  • Download 2012 report PDF
  • Download 2014 report PDF
  • Download 2015 report PDF
  • Contact us:

    Valid XHTML 1.0 Transitional