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

Common Yellowthroat Population Trend in Iowa

All statesForest birds

Common Yellowthroat in Iowa has declined: down 28% on the route-weighted index since 1969.

-28%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 →
57YearsYears 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 stay roughly flat through 2029, near 15 (95% range 9.5–21). A 5-year backtest shows a typical error of ±4.6%, with 100% of held-out values landing inside the 95% band.

-7%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 →
15Projected 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 →
9.5–2195% 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 →
±4.6%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 stay roughly flat through 2029, near 15 (95% range 9.5–21). A 5-year backtest shows a typical error of ±4.6%, with 100% of held-out values landing inside the 95% band.19672029
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 →
2025161022
2026169.922
2027169.822
2028169.621
2029159.521

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 →
Bedford4820181968
Bryant4320241967
Brooklyn4320221967
Wales3720181967
Festina3320241968
Davis Corner3020241968
West Liberty2920241968
College Spgs 22520232005
Red Rock2320241968
Washta2320141967
Maquoketa2220241967
Mt Hamill2020241967
Williamsburg2020231967
Melrose1920241974
Cedar Valley1819971967
Burchinal1820241995
Zearing1619951967
Lafayette1620242003
College Spgs1520041967
Kanawha1520241967
Clare1420191967
Exline1220241974
Panther1220241967
Scranton1220241967
Alice1119991967

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 2026-05-22.