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Species · Iowa · BBS 2025 Release · 1966–2024

Black-capped Chickadee Population Trend in Iowa

All statesForest birds

Black-capped Chickadee in Iowa has declined: down 41% on the route-weighted index since 1969.

-41%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 →
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 →
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 Black-capped Chickadee 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 Black-capped Chickadee in Iowa. See the full index history below.

Black-capped Chickadee Population Forecast in Iowa

If the recent trend holds, Black-capped Chickadee in Iowa is projected to rise about 28% by 2029 — from 0.95 in 2024 to a central estimate of 1.2 (95% range 0.20–2.2). A 5-year backtest shows a typical error of ±35.7%, with 100% of held-out values landing inside the 95% band.

+28%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 →
1.2Projected 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 →
0.20–2.295% 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 →
±35.7%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, Black-capped Chickadee in Iowa is projected to rise about 28% by 2029 — from 0.95 in 2024 to a central estimate of 1.2 (95% range 0.20–2.2). A 5-year backtest shows a typical error of ±35.7%, 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 →
20251.30.232.3
20261.20.222.3
20271.20.212.3
20281.20.202.2
20291.20.202.2

Black-capped Chickadee Survey Routes in Iowa

Routes recording Black-capped Chickadee 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 →
Alice819991967
Red Rock620241968
Wales620161968
Hudson620221968
Washington420221967
Clare420181975
Davis Corner420211980
Bedford320151969
Maquoketa320231968
Sioux City320241968
Rock Valley320151968
Melrose220241975
West Liberty220241969
Brooklyn220101967
Desmoines219781968
Prairieburg220181979
Dinsdale220241969
Washta220141967
Festina220241968
Garner219881975
Tipton220171993
Mccallsburg220192010
Mt Hamill120241967
Exline120241974
College Spgs120041967

Black-capped Chickadee Population Trend in Other States

alaskacaliforniacoloradoconnecticutidahoillinoisindianakansasmainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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