BirdAnalyst
Species · Iowa · BBS 2026 Release · 1966–2025

Gray Catbird Population Trend in Iowa

All statesForest birds

Gray Catbird in Iowa has surged: up 156% on the route-weighted index since 1969.

+156%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 Gray Catbird 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 →

Gray Catbird has surged in Iowa: up 156% on the route-weighted index since 1969.

Gray Catbird Population Forecast in Iowa

If the recent trend holds, Gray Catbird in Iowa is projected to rise about 32% by 2030 — from 7.0 in 2025 to a central estimate of 9.3 (95% range 7.6–11). A 5-year backtest shows a typical error of ±8.7%, with 80% of held-out values landing inside the 95% band.

+32%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 →
9.3Projected 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 →
7.6–1195% 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 →
±8.7%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, Gray Catbird in Iowa is projected to rise about 32% by 2030 — from 7.0 in 2025 to a central estimate of 9.3 (95% range 7.6–11). A 5-year backtest shows a typical error of ±8.7%, with 80% 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 →
20268.87.110
20278.97.211
20289.07.411
20299.27.511
20309.37.611

Gray Catbird Survey Routes in Iowa

Routes recording Gray Catbird 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 Rock2720251968
Mt Hamill2020251967
Bedford1820251968
Festina1820251968
Hudson1620251967
Exline1420251974
Maquoketa1120251967
Melrose1020251974
West Liberty920251969
Alice919991967
College Spgs 2820252006
Wales720251967
Lafayette720252003
Davis Corner620251968
College Spgs520041967
Panther520251967
Mccallsburg520251997
Pierson420251968
Washta420251967
Titonka420251968
Bryant320251967
Cedar Valley319971970
Brooklyn320251967
Washington320251967
Prairieburg320251967

Gray Catbird Population Trend in Other States

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

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