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

Yellow-billed Cuckoo Population Trend in Iowa

All statesGeneralists

Yellow-billed Cuckoo in Iowa has fallen sharply: down 71% on the route-weighted index since 1969.

-71%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 Yellow-billed Cuckoo 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 declinecomputed 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 →

Yellow-billed Cuckoo has fallen sharply in Iowa: down 71% on the route-weighted index since 1969.

Yellow-billed Cuckoo Population Forecast in Iowa

If the recent trend holds, Yellow-billed Cuckoo in Iowa is projected to rise about 222% by 2029 — from 0.18 in 2024 to a central estimate of 0.59 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±144.9%, with 100% of held-out values landing inside the 95% band.

+222%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 →
0.59Projected 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 →
0.00–1.495% 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 →
±144.9%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, Yellow-billed Cuckoo in Iowa is projected to rise about 222% by 2029 — from 0.18 in 2024 to a central estimate of 0.59 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±144.9%, 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 →
20250.630.001.4
20260.620.001.4
20270.610.001.4
20280.600.001.4
20290.590.001.4

Yellow-billed Cuckoo Survey Routes in Iowa

Routes recording Yellow-billed Cuckoo 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 →
College Spgs2520041968
Bedford820181968
Wales420181969
Hudson420211967
Melrose320221978
Exline220241974
Bryant220181967
Williamsburg220111970
Desmoines219781972
Festina220211969
Tipton220191999
Lafayette220192004
Mt Hamill120241967
West Liberty120211968
Cedar Valley119961967
Brooklyn120211967
Red Rock120191968
Panther120221967
Washington120221968
Neola120141968
Maquoketa120221969
Alice119961967
Prairieburg119991971
Dinsdale120051969
Kanawha120191967

Yellow-billed Cuckoo Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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