BirdAnalyst
Species · Utah · BBS 2025 Release · 1966–2024

Wilson's Phalarope Population Trend in Utah

All statesShorebirds

Wilson's Phalarope in Utah has collapsed: down 94% on the route-weighted index since 1985.

-94%Since 1985TrendPercent 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 →
19Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
36YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Wilson's Phalarope Trends in UtahNotable 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 →

Wilson's Phalarope has collapsed in Utah: down 94% on the route-weighted index since 1985.

Wilson's Phalarope Population Forecast in Utah

If the recent trend holds, Wilson's Phalarope in Utah is projected to rise about 172% by 2029 — from 0.14 in 2024 to a central estimate of 0.37 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±558.1%, with 100% of held-out values landing inside the 95% band.

+172%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 →
0.37Projected 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 →
0.00–2.395% 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 →
±558.1%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, Wilson's Phalarope in Utah is projected to rise about 172% by 2029 — from 0.14 in 2024 to a central estimate of 0.37 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±558.1%, with 100% of held-out values landing inside the 95% band.19742029
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 →
20250.480.002.4
20260.450.002.4
20270.420.002.4
20280.400.002.3
20290.370.002.3

Wilson's Phalarope Survey Routes in Utah

Routes recording Wilson's Phalarope in Utah.
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 →
Promontory7520161974
Saleratus Cr1220161997
Lynn1020211992
Neponset Res920181995
Grouse Creek819831983
E. Bear Lake620211999
Oak City620001985
Soapstone520012001
Callao520241992
Bear River420231992
Woodruff320042002
Goshen220242001
Wellington 2220092009
Snowville220222015
Vernal220182003
Heber Mtn.220162004
Gold Hill220181994
Randolph120241992
Shivwitz120212021

Wilson's Phalarope Population Trend in Other States

californiacoloradoidahoillinoisiowakansasminnesotamontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexaswashingtonwisconsinwyoming

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