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

Common Nighthawk Population Trend in Iowa

All statesAerial insectivores

Common Nighthawk in Iowa has edged down: down 24% on the route-weighted index since 1969.

-24%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 →
30Routes 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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Common Nighthawk 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 Common Nighthawk in Iowa. See the full index history below.

Common Nighthawk Population Forecast in Iowa

If the recent trend holds, Common Nighthawk in Iowa is projected to rise about 200% by 2029 — from 0.09 in 2024 to a central estimate of 0.27 (95% range 0.00–0.66). A 5-year backtest shows a typical error of ±136.1%, with 100% of held-out values landing inside the 95% band.

+200%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 →
0.27Projected 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 →
0.00–0.6695% 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 →
±136.1%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, Common Nighthawk in Iowa is projected to rise about 200% by 2029 — from 0.09 in 2024 to a central estimate of 0.27 (95% range 0.00–0.66). A 5-year backtest shows a typical error of ±136.1%, 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 →
20250.290.000.68
20260.280.000.67
20270.280.000.67
20280.280.000.67
20290.270.000.66

Common Nighthawk Survey Routes in Iowa

Routes recording Common Nighthawk 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 →
Desmoines2219791968
Wales1120132001
Cedar Valley519711971
Sioux City520211968
Exline219921992
Mt Hamill120081989
Melrose120131983
College Spgs119881979
Bryant120161967
West Liberty120241969
Williamsburg119871987
Red Rock120151996
Panther120072007
Washington119941984
Neola119921992
Maquoketa120001968
Alice119851985
Prairieburg119931993
Dinsdale119861986
Zearing119921967
Scranton120192019
Clare119781975
Pierson119901973
Washta120121979
Festina119701970

Common Nighthawk 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.