BirdAnalyst
Species · BCR 10 · BBS 2026 Release · 1966–2025

Tree Swallow In Northern Rockies

All regionsNorthern RockiesAerial insectivores

Tree Swallow in Northern Rockies has increased: up 40% on the route-weighted index since 1970.

+40%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 →
185Routes 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 →
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 SignalsNotable 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 Tree Swallow in Northern Rockies. See the full index history below.

Tree Swallow In Northern Rockies Population Forecast

If the recent trend holds, Tree Swallow in Northern Rockies is projected to stay roughly flat through 2030, near 5.8 (95% range 3.4–8.3). A 5-year backtest shows a typical error of ±6.5%, with 100% of held-out values landing inside the 95% band.

-1%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 →
5.8Projected 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 →
3.4–8.395% 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 →
±6.5%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, Tree Swallow in Northern Rockies is projected to stay roughly flat through 2030, near 5.8 (95% range 3.4–8.3). A 5-year backtest shows a typical error of ±6.5%, 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 →
20265.83.38.2
20275.83.38.2
20285.83.38.2
20295.83.48.3
20305.83.48.3

Routes In Northern Rockies

Routes recording Tree Swallow in Northern Rockies.
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 →
Red RockMONTANA1072025
NaplesIDAHO892025
CascadeIDAHO711984
Green RiverWYOMING671984
YellowstoneWYOMING502025
KalispellMONTANA362025
ChestnutMONTANA352025
BoulderWYOMING322025
Pablo Res.MONTANA302025
Hebgen LakeMONTANA302025
EllistonMONTANA272025
Ne EntranceWYOMING252025
Willow Creek 2MONTANA202025
VictorMONTANA192025
SeedskadeeWYOMING192023
CabartonIDAHO182024
Seedskadee 2WYOMING182024
LimaMONTANA172025
HarmonyWYOMING172025
NezperceIDAHO162007
Clyde ParkMONTANA162025
Hayden ValWYOMING161986
Logan PassMONTANA152025
Fort LoganMONTANA142025
DuboisWYOMING142025

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