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Species · Iowa · BBS 2026 Release · 1966–2025

Great Crested Flycatcher Population Trend in Iowa

All statesAerial insectivores

Great Crested Flycatcher in Iowa has held roughly steady: down 4% on the route-weighted index since 1969.

-4%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 →
39Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Great Crested Flycatcher Trends in IowaNotable 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 Great Crested Flycatcher in Iowa. See the full index history below.

Great Crested Flycatcher Population Forecast in Iowa

If the recent trend holds, Great Crested Flycatcher in Iowa is projected to fall about 21% by 2030 — from 1.4 in 2025 to a central estimate of 1.1 (95% range 0.47–1.7). A 5-year backtest shows a typical error of ±25%, with 100% of held-out values landing inside the 95% band.

-21%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 →
1.1Projected 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 →
0.47–1.795% 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 →
±25%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, Great Crested Flycatcher in Iowa is projected to fall about 21% by 2030 — from 1.4 in 2025 to a central estimate of 1.1 (95% range 0.47–1.7). A 5-year backtest shows a typical error of ±25%, 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 →
20261.10.501.7
20271.10.491.7
20281.10.481.7
20291.10.481.7
20301.10.471.7

Great Crested Flycatcher Survey Routes in Iowa

Routes recording Great Crested Flycatcher in Iowa.
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 →
Alice919991967
Red Rock620251969
Bedford520251968
Garner519931975
Washington420251967
Mt Hamill320251967
Maquoketa320251967
Dinsdale320251968
Washta320251976
Davis Corner320251968
Exline220251974
Brooklyn220181968
Neola220161968
Prairieburg220181967
Hudson220251968
Zearing219951968
Scranton220221968
Gaza220211979
Lafayette220252003
Melrose120231974
College Spgs120031967
Bryant120251967
West Liberty120181968
Cedar Valley119911967
Williamsburg120231970

Great Crested Flycatcher Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsin

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.