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

Northern Rough-winged Swallow Population Trend in Idaho

All statesAerial insectivores

Northern Rough-winged Swallow in Idaho has declined: down 34% on the route-weighted index since 1970.

-34%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 →
55Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Northern Rough-winged Swallow Trends in IdahoNotable 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 Northern Rough-winged Swallow in Idaho. See the full index history below.

Northern Rough-winged Swallow Population Forecast in Idaho

If the recent trend holds, Northern Rough-winged Swallow in Idaho is projected to rise about 32% by 2030 — from 3.1 in 2025 to a central estimate of 4.1 (95% range 0.00–8.8). A 5-year backtest shows a typical error of ±24.1%, with 100% of held-out values landing inside the 95% band.

+32%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 →
4.1Projected 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 →
0.00–8.895% 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 →
±24.1%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, Northern Rough-winged Swallow in Idaho is projected to rise about 32% by 2030 — from 3.1 in 2025 to a central estimate of 4.1 (95% range 0.00–8.8). A 5-year backtest shows a typical error of ±24.1%, 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 →
20264.20.008.8
20274.20.008.8
20284.10.008.8
20294.10.008.8
20304.10.008.8

Northern Rough-winged Swallow Survey Routes in Idaho

Routes recording Northern Rough-winged Swallow in Idaho.
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 →
Naples8620251972
Glenns Ferry3219861968
Golden2620161987
Baker2420241974
Cedar Hill2020241989
Triangle1220211985
Pocatello720191979
Pasadena Val720161987
Leadore620241974
Henry619791973
Rochat Divde620251993
Daniels Res620191988
Nezperce Nf619991992
Lost River520222005
Cape Horn519921992
Challis520191976
Tractor Flat520082006
Burgdorf520031990
Crane Creek520191989
Featherville520221989
Nezperce420121968
Dubois420251969
Magic Mtn420251987
Lolo Pass320191996
Twin Buttes320001998

Northern Rough-winged Swallow Population Trend in Other States

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

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