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Species · Delaware · BBS 2025 Release · 1966–2024

Common Nighthawk Population Trend in Delaware

All statesAerial insectivores

Common Nighthawk in Delaware has collapsed: down 89% on the route-weighted index since 1969.

-89%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 →
5Routes 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 →
21YearsYears 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 DelawareNotable 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 →

Common Nighthawk has collapsed in Delaware: down 89% on the route-weighted index since 1969.

Common Nighthawk Population Forecast in Delaware

If the recent trend holds, Common Nighthawk in Delaware is projected to rise about 103% by 2014 — from 0.13 in 2009 to a central estimate of 0.25 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±933.6%, with 60% of held-out values landing inside the 95% band.

+103%Change by 2014TrendPercent 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 →
0.25Projected 2014 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.995% 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 →
±933.6%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 Delaware is projected to rise about 103% by 2014 — from 0.13 in 2009 to a central estimate of 0.25 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±933.6%, with 60% of held-out values landing inside the 95% band.19662014
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 →
20100.360.002.0
20110.330.002.0
20120.310.001.9
20130.280.001.9
20140.250.001.9

Common Nighthawk Survey Routes in Delaware

Routes recording Common Nighthawk in Delaware.
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 →
Bethany Bch419901966
Wilmington119671967
Harrington120091992
Dover119671967
Milton119711971

Common Nighthawk Population Trend in Other States

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

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