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

Gray Catbird Population Trend in Iowa

All statesGeneralists

Gray Catbird in Iowa has surged: up 183% on the route-weighted index since 1969.

+183%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 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 183% 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 stay roughly flat through 2029, near 9.3 (95% range 7.7–11). A 5-year backtest shows a typical error of ±7.1%, with 100% of held-out values landing inside the 95% band.

+9%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 →
9.3Projected 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 →
7.7–1195% 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 →
±7.1%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, Gray Catbird in Iowa is projected to stay roughly flat through 2029, near 9.3 (95% range 7.7–11). A 5-year backtest shows a typical error of ±7.1%, 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 →
20258.87.210
20268.97.311
20279.07.411
20289.27.511
20299.37.711

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 Rock3320241968
College Spgs 22120232006
Maquoketa2020241967
Bedford1920181968
Festina1720241968
Lafayette1720242003
Exline1420241974
West Liberty1420241969
Mt Hamill1220241967
Melrose1220241974
Wales1020181967
Brooklyn920221967
Alice919991967
Washta920141967
Panther820241967
Hudson820221967
Davis Corner620241968
Tipton620241993
College Spgs520041967
Kanawha520241976
Sioux City520241970
Washington420241967
Pierson420191968
Cedar Valley319971970
Zearing319951967

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 2026-05-22.