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

Least Flycatcher Population Trend in Washington

All statesAerial insectivores

Least Flycatcher in Washington has declined: down 37% on the route-weighted index since 1986.

-37%Since 1986TrendPercent 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 →
16Routes 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 →
26YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Least Flycatcher Trends in WashingtonNotable 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 Least Flycatcher in Washington. See the full index history below.

Least Flycatcher Population Forecast in Washington

If the recent trend holds, Least Flycatcher in Washington is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±75.2%, with 80% of held-out values landing inside the 95% band.

n/aChange 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 →
0.02Projected 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 →
0.00–0.1195% 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 →
±75.2%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, Least Flycatcher in Washington is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±75.2%, with 80% of held-out values landing inside the 95% band.19792029
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 →
20250.030.000.11
20260.020.000.11
20270.020.000.11
20280.020.000.11
20290.020.000.11

Least Flycatcher Survey Routes in Washington

Routes recording Least Flycatcher in Washington.
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 →
Newhalem819861986
Turnbull Nwr620232011
Ewan220072001
Laurier220012001
Nighthawk220101995
Cusick120111995
Wilbur119931993
Chewelah120191979
Northport120231998
L Pend O Nwr120242013
Reardan120052005
Yakima120102010
Curlew120131993
Lake Chelan120232023
Winthrop119831983
Tonasket120062006

Least Flycatcher Population Trend in Other States

alaskaarkansascaliforniacoloradoconnecticutgeorgiaidahoillinoisindianaiowakentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseeutahvermontvirginiawest-virginiawisconsinwyoming

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