BirdAnalyst
Species · BCR 37 · BBS 2025 Release · 1966–2024

Long-billed Thrasher In Gulf Coastal Prairie

All regionsGulf Coastal PrairieGeneralists

Long-billed Thrasher in Gulf Coastal Prairie has surged: up 12× on the route-weighted index since 1973.

12×Since 1973TrendPercent 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 →
8Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
41YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 increasecomputed 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 →

Long-billed Thrasher has surged in Gulf Coastal Prairie: up 12× on the route-weighted index since 1973.

Long-billed Thrasher In Gulf Coastal Prairie Population Forecast

If the recent trend holds, Long-billed Thrasher in Gulf Coastal Prairie is projected to rise about 190% by 2029 — from 0.52 in 2024 to a central estimate of 1.5 (95% range 0.42–2.6). A 5-year backtest shows a typical error of ±67.1%, with 100% of held-out values landing inside the 95% band.

+190%Change 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 →
1.5Projected 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 →
0.42–2.695% 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 →
±67.1%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, Long-billed Thrasher in Gulf Coastal Prairie is projected to rise about 190% by 2029 — from 0.52 in 2024 to a central estimate of 1.5 (95% range 0.42–2.6). A 5-year backtest shows a typical error of ±67.1%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20251.40.312.5
20261.40.342.5
20271.50.372.6
20281.50.392.6
20291.50.422.6

Routes In Gulf Coastal Prairie

Routes recording Long-billed Thrasher in Gulf Coastal Prairie.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
L. Atascosa NwrTEXAS92023
Loyola Beach 2TEXAS72024
Loyola BeachTEXAS62009
San PedroTEXAS52023
Lag AtascosaTEXAS42024
PetronilaTEXAS12021
IndianolaTEXAS12002
BaysideTEXAS12010

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.