Toxostoma bendirei 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Passeriformes Mimidae

Scientific Name: Toxostoma bendirei
Species Authority: (Coues, 1873)
Common Name(s):
English Bendire's Thrasher
Identification information: 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.

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2ce+3ce+4ce ver 3.1
Year Published: 2012
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Inigo, E., Rosenberg, K. & Wells, J.
Facilitator/Compiler(s): Benstead, P., Bird, J., Harding, M., Sharpe, C J
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.

Previously published Red List assessments:
2008 Vulnerable (VU)
2004 Vulnerable (VU)
2000 Lower Risk/least concern (LR/lc)
1994 Lower Risk/least concern (LR/lc)
1988 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Range Description: Toxostoma bendirei is found in south-west USA and north-west Mexico, from 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 and confusion with other similar Toxostoma species) (England and Laudenslayer 1993). Individuals in the northern portion of the range migrate south in the winter and overlap with more southern residents (England and Laudenslayer 1993, Brewer and MacKay 2001). The species is now so rare that trends cannot be estimated reliably from Breeding Bird Survey data (J. Wells, K. Rosenberg and E. Inigo in litt. 2003), but declines between 1966 and 2003 equate to 34.5%.

Countries occurrence:
Mexico; United States
Present - origin uncertain:
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 823000
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Upper elevation limit (metres): 1600
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Rich et al. (2003).

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). The BBS trend analyses for the ten-year period from 1993-2002 and the 21-year period 1980-2002 show no significant trends, but this is attributable to the fact that few birds are encountered anymore because they are so rare across the species range (J. Wells, K. Rosenberg and E. Inigo in litt. 2003).
Current Population Trend: Decreasing
Additional data:
Continuing decline of mature individuals: Unknown
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology: 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).

Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 4.2
Movement patterns: Full Migrant

Threats [top]

Major Threat(s): 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.

Conservation Actions [top]

Conservation Actions: 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. No information exists on other management actions (England and Laudenslayer 1993). The species occurs within a number of protected areas.

Conservation Actions Proposed
Research its ecology and determine key habitat requirements. Research the benefits of an increase in scattered junipers from grazing. Study potential competition with Curve-billed Thrashers. Avoid disturbance to and development of important habitats. Determine the taxonomy of Baha Californian populations.

Citation: BirdLife International. 2012. Toxostoma bendirei. The IUCN Red List of Threatened Species 2012: e.T22711108A39682026. . Downloaded on 26 November 2015.
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