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

Willow Flycatcher Population Trend in Utah

All statesAerial insectivores

Willow Flycatcher in Utah has edged down: down 22% on the route-weighted index since 1974.

-22%Since 1974TrendPercent 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 →
38Routes 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 →
43YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Willow Flycatcher 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 →

No notable trend signals for Willow Flycatcher in Utah. See the full index history below.

Willow Flycatcher Population Forecast in Utah

If the recent trend holds, Willow Flycatcher in Utah is projected to fall about 37% by 2029 — from 0.15 in 2024 to a central estimate of 0.10 (95% range 0.00–0.32). A 5-year backtest shows a typical error of ±61.8%, with 80% of held-out values landing inside the 95% band.

-37%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 →
0.10Projected 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 →
0.00–0.3295% 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 →
±61.8%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, Willow Flycatcher in Utah is projected to fall about 37% by 2029 — from 0.15 in 2024 to a central estimate of 0.10 (95% range 0.00–0.32). A 5-year backtest shows a typical error of ±61.8%, with 80% of held-out values landing inside the 95% band.19702029
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 →
20250.110.000.34
20260.110.000.33
20270.100.000.33
20280.100.000.33
20290.100.000.32

Willow Flycatcher Survey Routes in Utah

Routes recording Willow Flycatcher 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 →
Ant Flat-Ogden Can1120232005
Navajo Lake419741974
Jensen420242008
Promontory320052005
Timpie Spg320021978
Lost Cr. Res220081995
Woodruff220232005
Soapstone220191992
Skyline Driv220071986
Hanna220242000
Green River220082008
Gold Hill220192019
Blanding219921992
Moon Lake 2120152014
Beck119741971
Altonah120071978
Neponset Res120002000
Logan Canyon120062006
Goshen120101970
Bryce Canyon120052005
Beaver119851985
Hanksville120112011
Boulder120001988
Aneth120242024
Lynn120231986

Willow Flycatcher Population Trend in Other States

alaskaarizonaarkansascaliforniacoloradoconnecticutdelawaregeorgiaidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasvermontvirginiawashingtonwest-virginiawisconsinwyoming

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