BirdAnalyst
Species · BBS 2025 Release · 1966–2024

LeConte's Thrasher

MimidaeArid-land birdsToxostoma lecontei

LeConte's Thrasher has collapsed: down 97% on the route-weighted index since 1970.

-97%Since 1970TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
63RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the LeConte's Thrasher

The LeConte's Thrasher (Toxostoma lecontei) is a North American member of the Mockingbirds & Thrashers (Mimidae). In this analysis it is grouped with the arid-land birds.

Size
8–12 in long (20–30 cm) — a slender, long-tailed songbird (typical for the family)
Habitat
Deserts, dry scrub and brushland of the Southwest.
Diet
Seeds, insects and cactus fruit of arid-land plants.
Range
Recorded on 63 Breeding Bird Survey routes across 4 states, most concentrated in the Sonoran and Mojave Deserts.
Family
Mimidae · Arid-land birds

Notable LeConte's Thrasher TrendsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

LeConte's Thrasher has collapsed in surveyed states: down 97% on the route-weighted index since 1970.

LeConte's Thrasher Population Forecast

If the recent trend holds, LeConte's Thrasher is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.02). A 5-year backtest shows a typical error of ±370.3%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.00Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0295% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±370.3%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, LeConte's Thrasher is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.02). A 5-year backtest shows a typical error of ±370.3%, with 100% of held-out values landing inside the 95% band.19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20250.000.000.02
20260.000.000.02
20270.000.000.02
20280.000.000.02
20290.000.000.02

Where the LeConte's Thrasher Is Detected

BBS routes recording LeConte's Thrasher, sized by most recent count.

LeConte's Thrasher Population Trend by State

LeConte's Thrasher population trend by state.
TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Arizona-95%197014
California-97%197043
Nevada-60%19935
Utahinsufficient datan/a1

LeConte's Thrasher Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

LeConte's Thrasher population trend by Bird Conservation Region.
TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Coastal California-93%19706
Sonoran and Mojave Deserts-97%197056

LeConte's Thrasher Conservation Status

Our route-weighted index shows it down about 97% since 1970.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.