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Species · Iowa · BBS 2026 Release · 1966–2025

Common Yellowthroat Population Trend in Iowa

All statesForest birds

Common Yellowthroat in Iowa has edged down: down 24% on the route-weighted index since 1969.

-24%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 Common Yellowthroat 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 Common Yellowthroat in Iowa. See the full index history below.

Common Yellowthroat Population Forecast in Iowa

If the recent trend holds, Common Yellowthroat in Iowa is projected to fall about 21% by 2030 — from 20 in 2025 to a central estimate of 16 (95% range 9.6–21). A 5-year backtest shows a typical error of ±6.1%, 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 →
16Projected 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 →
9.6–2195% 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 →
±6.1%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, Common Yellowthroat in Iowa is projected to fall about 21% by 2030 — from 20 in 2025 to a central estimate of 16 (95% range 9.6–21). A 5-year backtest shows a typical error of ±6.1%, 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 →
2026161022
2027161022
2028169.922
2029169.822
2030169.621

Common Yellowthroat Survey Routes in Iowa

Routes recording Common Yellowthroat 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 →
Bedford4920251968
Bryant4420251967
Festina3720251968
Hudson3420251967
Wales3220251967
Brooklyn3120251967
Davis Corner3020251968
Pierson2820251968
Exline2620251974
College Spgs 22520252005
Mt Hamill2420251967
Red Rock2120251968
Williamsburg2020231967
Melrose1820251974
Cedar Valley1819971967
Titonka1820251968
Burchinal1820251995
West Liberty1720251968
Prairieburg1720251967
Maquoketa1620251967
Zearing1619951967
College Spgs1520041967
Panther1420251967
Clare1420191967
Lafayette1320252003

Common Yellowthroat Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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