BirdAnalyst
Species · BCR 34 · BBS 2025 Release · 1966–2024

Common Nighthawk In Sierra Madre Occidental

All regionsSierra Madre OccidentalAerial insectivores

Common Nighthawk in Sierra Madre Occidental has fallen sharply: down 73% on the route-weighted index since 1970.

-73%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 →
27Routes In RegionSurvey 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 SignalsNotable 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 fallen sharply in Sierra Madre Occidental: down 73% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Common Nighthawk in Sierra Madre Occidental is projected to fall about 10% by 2029 — from 0.94 in 2024 to a central estimate of 0.85 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±86%, with 100% of held-out values landing inside the 95% band.

-10%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 →
0.85Projected 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 →
0.00–2.395% 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 →
±86%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 Sierra Madre Occidental is projected to fall about 10% by 2029 — from 0.94 in 2024 to a central estimate of 0.85 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±86%, with 100% 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 →
20250.900.002.3
20260.880.002.3
20270.870.002.3
20280.860.002.3
20290.850.002.3

Routes In Sierra Madre Occidental

Routes recording Common Nighthawk in Sierra Madre Occidental.
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 →
Mormon LakeARIZONA111975
MagdalenaNEW-MEXICO92024
Peña BlancaARIZONA81984
SunizonaARIZONA51986
Happy JackARIZONA42024
ReserveNEW-MEXICO32021
FlagstaffARIZONA22022
BlueARIZONA21991
MaineARIZONA22017
Skull ValleyARIZONA22023
AlpineARIZONA22017
McnealARIZONA22024
Emory PassNEW-MEXICO22023
PrescottARIZONA12014
PomereneARIZONA12019
San SimonARIZONA12016
PatagoniaARIZONA12003
WilliamsARIZONA12019
Tonto Vill.ARIZONA12016
Forest LakesARIZONA12024
PinetopARIZONA12022
AmadoARIZONA11999
Clay SpringARIZONA12021
SprucedaleARIZONA12023
Sunizona 2ARIZONA12022

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