BirdAnalyst
Species · BBS 2026 Release · 1966–2025

Long-billed Curlew Population Analysis

ScolopacidaeShorebirdsNumenius americanus

Long-billed Curlew has surged: up 401% on the route-weighted index since 1969.

+401%Since 1969TrendPercent 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 →
459RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58Years 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 Long-billed Curlew

The Long-billed Curlew (Numenius americanus) is a North American member of the Sandpipers & Allies (Scolopacidae). In this analysis it is grouped with the shorebirds.

Size
5–26 in long (13–66 cm) — a probing shorebird (typical for the family)
Habitat
Shorelines, mudflats, beaches, flooded fields and wet meadows.
Diet
Invertebrates probed or picked from mud, sand and shallow water.
Range
Recorded on 459 Breeding Bird Survey routes across 16 states, most concentrated in the Great Basin.
Family
Scolopacidae · Shorebirds

Notable Long-billed Curlew 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 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 surveyed states: up 401% on the route-weighted index since 1969.

Long-billed Curlew Population Forecast

If the recent trend holds, Long-billed Curlew is projected to rise about 34% by 2030 — from 0.27 in 2025 to a central estimate of 0.37 (95% range 0.26–0.47). A 5-year backtest shows a typical error of ±11.8%, with 100% of held-out values landing inside the 95% band.

+34%Change by 2030TrendPercent 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 →
0.37Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.26–0.4795% 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 →
±11.8%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 is projected to rise about 34% by 2030 — from 0.27 in 2025 to a central estimate of 0.37 (95% range 0.26–0.47). A 5-year backtest shows a typical error of ±11.8%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.350.250.46
20270.360.250.47
20280.360.250.47
20290.360.260.47
20300.370.260.47

Where the Long-billed Curlew Is Detected

BBS routes recording Long-billed Curlew, sized by most recent count.

Long-billed Curlew Population Trend by State

Long-billed Curlew 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 →
California-95%197222
Colorado-92%197333
Idaho+18%197238
Kansas-20%19746
Montana+378%197079
Nebraska-13%196926
Nevada+404%197023
New Mexico-37%197023
North Dakota+22%19735
Oklahoma+275%19715
Oregon-3%197145
South Dakota+41%196928
Texas+278%196929
Utah-25%197032
Washington-85%197624
Wyoming+68%198141

Long-billed Curlew Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Long-billed Curlew 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 →
Great Basin+83%1970145
Northern Rockies+48%197080
Prairie Potholes13×197020
Southern Rockies / Colorado Plateau+33%199112
Badlands and Prairies+237%196979
Shortgrass Prairie-3%196971
Central Mixed Grass Prairie-11%196919
Coastal California-60%19729
Gulf Coastal Prairie+13%197512

Long-billed Curlew Conservation Status

Our route-weighted index shows it up about 401% since 1969. Many shorebirds have declined steeply, reflecting pressure on the coastal and wetland stopovers they depend on.

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. Trend is a route-weighted relative-abundance index, not an absolute population.