Data Zone
Justification of Red List category
This species is listed as Vulnerable because it is suspected to be undergoing a rapid decline. However, recent trends are poorly documented, and further information may warrant a revision of its status. Putative threats are poorly understood, but the species may be negatively impacted by habitat destruction and degradation resulting from agricultural expansion and development, as well as climate change.
Population justification
Partners in Flight (2019) estimate the global population to total 83,000 mature individuals.
Trend justification
This species has undergone a large and statistically significant decrease over the last 40 years in North America (-90.6% decline over 40 years, equating to a -44.7% decline per decade; data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007). Partners in Flight (2019) currently estimate that the species could undergo a 50% population reduction across the next 18 years and that the current rate of annual decline is ~4.3%. This equates to a ~35.4% decline across the following ten-year period, hence the species is likely undergoing a continuing decline, placed here in the range 30-49%.
Toxostoma bendirei is found in south-west U.S.A. and north-west Mexico, from Mojave desert in California east into southern Nevada, southern Utah and south-western Colorado south to central Sonora. Its status in Baja California is unresolved (England and Laudenslayer 1993, Brewer and MacKay 2001). Within this range its distribution is patchy and in some cases poorly known (owing to low observer density in desert regions) (England and Laudenslayer 1993). Individuals in the northern portion of the range migrate east and south in the winter and overlap with more eastern and southern residents (England and Laudenslayer 1993, Brewer and MacKay 2001). The species is becoming increasingly rare with Partners in Flight (2019) currently estimating an annual population decline of ~4.3%.
It is found in sparse desert habitats from sea level in Sonora to approximately 1,800 m in Utah (England and Laudenslayer 1993, Brewer and MacKay 2001). Throughout its range, breeders favour relatively open grassland, shrubland or woodland with scattered shrubs or trees; it is not found in dense vegetation. It forages primarily on the ground, probing for insects and other arthropods, but will also eat seeds and berries (England and Laudenslayer 1993). It also digs with its bill, but less frequently, not as powerfully nor as efficiently as other thrashers (England and Laudenslayer 1993). In the Mojave desert, California, migration begins as soon as breeding finishes, with breeding grounds vacated by late August (Brewer and MacKay 2001).
Populations have been eliminated by dense urbanisation around Tucson and by large scale agriculture along the Gila River. In California potential threats may include harvesting of Joshua trees and other yuccas, overgrazing and off-road vehicle activity. However, there have been suggestions that clearing and agricultural activities actually favour this species (England and Laudenslayer 1993). Competition with the Curve-billed Thrasher Toxostroma curvirostre for a depleted food supply may have contributed to a decline in the population. Breeding is delayed and potentially less successful as a result of drought conditions (McCreedy and van Ripper III 2015), which may increase in line with climate change, and thus this could be a significant threat into the future. Energy/resource extraction is also listed in Rosenberg et al. (2016) as a potential threat to this species with alternative energy development occurring in the Sonoran desert.
Conservation Actions Underway
The species has been classified as a "Species of Special Concern" by California Department of Fish and Game, and protected from take. It is classified as a C1 “Species of Greatest Conservation Need” by Arizona Game and Fish Department. No information exists on other management actions (England and Laudenslayer 1993). The species occurs within a number of protected areas. Recently a Desert Thrashers Working Group has been formed to determine what management actions need to be taken (C. Beardmore in litt. 2016).
25 cm. Small, drab almost uniformly brown thrasher. Similar spp. Told from similar Curve-billed Thrasher T. curvirostre by its smaller size; shorter, straighter bill; paler, yellow iris; small triangular (not round) spots on breast; buffy (not dark) malar; and buff-brown (not grayish) flanks. Voice Slow choppy phrases of semi-musical thrush-like whistles and chattering calls.
Text account compilers
Everest, J.
Contributors
Beardmore, C., Benstead, P., Bird, J., Harding, M., Inigo, E., McCreedy, C., Rosenberg, K., Sharpe, C.J. & Wells, J.
Recommended citation
BirdLife International (2024) Species factsheet: Bendire's Thrasher Toxostoma bendirei. Downloaded from
https://datazone.birdlife.org/species/factsheet/bendires-thrasher-toxostoma-bendirei on 23/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 23/11/2024.