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

Chipping Sparrow Population Trend in Iowa

All statesGeneralists

Chipping Sparrow in Iowa has surged: up 645% on the route-weighted index since 1969.

+645%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 Chipping Sparrow 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 →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Chipping Sparrow has surged in Iowa: up 645% on the route-weighted index since 1969.

Chipping Sparrow Population Forecast in Iowa

If the recent trend holds, Chipping Sparrow in Iowa is projected to rise about 73% by 2029 — from 9.3 in 2024 to a central estimate of 16 (95% range 12–21). A 5-year backtest shows a typical error of ±62.4%, with 20% of held-out values landing inside the 95% band.

+73%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 →
16Projected 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 →
12–2195% 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 →
±62.4%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, Chipping Sparrow in Iowa is projected to rise about 73% by 2029 — from 9.3 in 2024 to a central estimate of 16 (95% range 12–21). A 5-year backtest shows a typical error of ±62.4%, with 20% 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 →
2025151120
2026151120
2027161120
2028161220
2029161221

Chipping Sparrow Survey Routes in Iowa

Routes recording Chipping Sparrow 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 →
Red Rock4320241968
Panther2620241967
Cedar Valley2219971971
College Spgs 21920232005
College Spgs1420041989
Washta1420141975
Neola1320161968
Sioux City1320241968
Alice1219991968
Zearing1219951974
Festina1220241968
Bryant1120241967
West Liberty1120241969
Hudson1120221967
Wales1020181989
Rock Valley1020241968
Lafayette1020242003
Davis Corner920241972
Garner919931973
Burchinal920241995
Pierson820191968
Mccallsburg720241996
Melrose620241977
Maquoketa620241968
Scranton620241971

Chipping Sparrow 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.