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

Common Nighthawk Population Trend in California

All statesAerial insectivores

Common Nighthawk in California has surged: up 214% on the route-weighted index since 1970.

+214%Since 1970TrendPercent 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 →
81Routes 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 →
56YearsYears 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 CaliforniaNotable 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 →

Common Nighthawk has surged in California: up 214% on the route-weighted index since 1970.

Common Nighthawk Population Forecast in California

If the recent trend holds, Common Nighthawk in California is projected to rise about 57% by 2029 — from 0.69 in 2024 to a central estimate of 1.1 (95% range 0.41–1.7). A 5-year backtest shows a typical error of ±159.5%, with 0% of held-out values landing inside the 95% band.

+57%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 →
1.1Projected 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 →
0.41–1.795% 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 →
±159.5%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 California is projected to rise about 57% by 2029 — from 0.69 in 2024 to a central estimate of 1.1 (95% range 0.41–1.7). A 5-year backtest shows a typical error of ±159.5%, with 0% of held-out values landing inside the 95% band.19682029
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 →
20251.00.381.7
20261.10.391.7
20271.10.401.7
20281.10.411.7
20291.10.411.7

Common Nighthawk Survey Routes in California

Routes recording Common Nighthawk in California.
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 →
Imperial Dam2219911987
Eagle Lake2020241970
Goumaz1920101997
Clear Lk Res1520181972
Tionesta1420211998
Crowley Lake1220241973
Ingalls1120001974
Honey Lake920241972
Hat Creek820181974
Little Truckee620231998
Pine Mountain620171998
Chilcoot620241998
Hackamore520072003
Madeline520241997
Lassen Park419881972
Dorris420191972
Iron Gate420191989
Crowder Flat420192002
Red Bluff320191968
Big Bear319861969
Macdoel320181980
Bridgeport319771977
Downieville320131975
Chaos Crater320181990
Nubieber220181972

Common Nighthawk Population Trend in Other States

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

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