BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Willet

ScolopacidaeShorebirdsTringa semipalmata

Willet has increased: up 49% on the route-weighted index since 1968.

+49%Since 1968TrendPercent 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 →
371RoutesSurvey 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 Willet

The Willet (Tringa semipalmata) 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 371 Breeding Bird Survey routes across 26 states, most concentrated in the Great Basin.
Family
Scolopacidae · Shorebirds

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

No notable trend signals for Willet. See the full index history below.

Willet Population Forecast

If the recent trend holds, Willet is projected to rise about 59% by 2029 — from 0.15 in 2024 to a central estimate of 0.24 (95% range 0.14–0.35). A 5-year backtest shows a typical error of ±53%, with 60% of held-out values landing inside the 95% band.

+59%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 →
0.24Projected 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 →
0.14–0.3595% 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 →
±53%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, Willet is projected to rise about 59% by 2029 — from 0.15 in 2024 to a central estimate of 0.24 (95% range 0.14–0.35). A 5-year backtest shows a typical error of ±53%, with 60% of held-out values landing inside the 95% band.19662029
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 →
20250.240.140.35
20260.240.140.35
20270.240.140.35
20280.240.140.35
20290.240.140.35

Where the Willet Is Detected

BBS routes recording Willet, sized by most recent count.

Willet Population Trend by State

Willet 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 →
Alabama-89%19684
California-43%197424
Coloradoinsufficient datan/a5
Connecticutinsufficient datan/a2
Delaware+15%19689
Florida-62%196819
Idaho-56%197220
Louisiana-88%197114
Maineinsufficient datan/a2
Maryland-67%19689
Massachusetts+227%19856
Minnesotainsufficient datan/a5
Montana+537%197146
Nebraska+17%19729
Nevada+216%199113
New Jersey-71%19804
New Yorkinsufficient datan/a2
North Carolina-88%19704
North Dakota+101%196942
Oregon+90%197227
South Carolinainsufficient datan/a2
South Dakota-49%196922
Texas-23%197020
Utah-87%197218
Virginia-43%19695
Wyoming+160%197938

Willet Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Willet 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-16%197184
Northern Rockies+32%197452
Prairie Potholes+112%196967
Sierra Nevada-91%19744
Badlands and Prairies+75%197143
Central Mixed Grass Prairie+77%19728
Southeastern Coastal Plain-82%196820
New England / Mid-Atlantic Coast-19%196837
Peninsular Florida-61%197110
Gulf Coastal Prairie-64%197030

Willet Conservation Status

Our route-weighted index shows it up about 49% since 1968. Many shorebirds have declined steeply, reflecting pressure on the coastal and wetland stopovers they depend on.

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