BirdAnalyst
Species · Colorado · BBS 2026 Release · 1966–2025

Bank Swallow Population Trend in Colorado

All statesAerial insectivores

Bank Swallow in Colorado has declined: down 46% on the route-weighted index since 1973.

-46%Since 1973TrendPercent 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 →
36Routes 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 →
43YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bank Swallow Trends in ColoradoNotable 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 Bank Swallow in Colorado. See the full index history below.

Bank Swallow Population Forecast in Colorado

If the recent trend holds, Bank Swallow in Colorado is projected to rise about 50% by 2030 — from 0.14 in 2025 to a central estimate of 0.21 (95% range 0.00–0.75). A 5-year backtest shows a typical error of ±972.7%, with 100% of held-out values landing inside the 95% band.

+50%Change by 2030TrendPercent 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 →
0.21Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.7595% 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 →
±972.7%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, Bank Swallow in Colorado is projected to rise about 50% by 2030 — from 0.14 in 2025 to a central estimate of 0.21 (95% range 0.00–0.75). A 5-year backtest shows a typical error of ±972.7%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20260.230.000.77
20270.220.000.77
20280.220.000.76
20290.210.000.76
20300.210.000.75

Bank Swallow Survey Routes in Colorado

Routes recording Bank Swallow in Colorado.
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 →
Dolores1819741974
Fort Morgan1220211998
Prospect Val1119921992
Arsenal1020152008
Lamar1019951973
Nunn1020252025
San Luis1020001997
Rifle Falls520251998
Parlin419831983
Browns Park420061994
Yellowjacket Pass420151999
Harmony319801980
Two Buttes319951982
Yampa220132008
Buford220211970
Wilson Creek219981990
Lay220181996
Antonito220001996
De Beque219951995
Paonia219981997
Piceance Basin220062004
Maybell120211994
Aspen119991986
Falfa119741974
Mica Butte119681968

Bank Swallow Population Trend in Other States

alabamaalaskaarkansascaliforniaconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.