BirdAnalyst
Species · BCR 11 · BBS 2025 Release · 1966–2024

Long-billed Curlew In Prairie Potholes

All regionsPrairie PotholesShorebirds

Long-billed Curlew in Prairie Potholes has surged: up 15× on the route-weighted index since 1970.

15×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 →
20Routes 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 →
53YearsYears 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 Curlew has surged in Prairie Potholes: up 15× on the route-weighted index since 1970.

Long-billed Curlew In Prairie Potholes Population Forecast

If the recent trend holds, Long-billed Curlew in Prairie Potholes is projected to fall about 24% by 2029 — from 1.1 in 2024 to a central estimate of 0.82 (95% range 0.36–1.3). A 5-year backtest shows a typical error of ±47.4%, with 20% of held-out values landing inside the 95% band.

-24%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 →
0.82Projected 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 →
0.36–1.395% 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 →
±47.4%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 Curlew in Prairie Potholes is projected to fall about 24% by 2029 — from 1.1 in 2024 to a central estimate of 0.82 (95% range 0.36–1.3). A 5-year backtest shows a typical error of ±47.4%, with 20% 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 →
20250.770.311.2
20260.780.321.2
20270.790.341.3
20280.810.351.3
20290.820.361.3

Routes In Prairie Potholes

Routes recording Long-billed Curlew in Prairie Potholes.
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 →
GildfordMONTANA172024
VirgelleMONTANA122024
RedstoneMONTANA112024
Ester LakeMONTANA92024
Great FallsMONTANA72024
GlentanaMONTANA72024
Hay LakeMONTANA62022
SunburstMONTANA42007
GlasgowMONTANA32024
OswegoMONTANA32024
SacoMONTANA32024
Sun RiverMONTANA32023
HarlemMONTANA22018
MaltaMONTANA22023
ShelbyMONTANA22024
LambertMONTANA22023
Eagle CreekNEBRASKA21971
ClevelandMONTANA12024
WhitlashMONTANA12024
ChinookMONTANA12024

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