BirdAnalyst
Species · BCR 12 · BBS 2026 Release · 1966–2025

Barn Swallow In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionAerial insectivores

Barn Swallow in Boreal Hardwood Transition has fallen sharply: down 74% on the route-weighted index since 1968.

-74%Since 1968TrendPercent 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 →
113Routes 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 →
59YearsYears 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 →

Barn Swallow has fallen sharply in Boreal Hardwood Transition: down 74% on the route-weighted index since 1968.

Barn Swallow In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Barn Swallow in Boreal Hardwood Transition is projected to fall about 64% by 2030 — from 2.1 in 2025 to a central estimate of 0.75 (95% range 0.00–3.8). A 5-year backtest shows a typical error of ±23.4%, with 100% of held-out values landing inside the 95% band.

-64%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 →
0.75Projected 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 →
0.00–3.895% 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 →
±23.4%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, Barn Swallow in Boreal Hardwood Transition is projected to fall about 64% by 2030 — from 2.1 in 2025 to a central estimate of 0.75 (95% range 0.00–3.8). A 5-year backtest shows a typical error of ±23.4%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20261.40.004.4
20271.20.004.3
20281.10.004.1
20290.910.003.9
20300.750.003.8

Routes In Boreal Hardwood Transition

Routes recording Barn Swallow in Boreal Hardwood Transition.
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 →
Wigwam BayMINNESOTA352023
BagleyMINNESOTA302006
Cedar RunMICHIGAN271999
BrainerdMINNESOTA192024
Grand ViewWISCONSIN142011
Hubbard LakeMICHIGAN111996
WarroadMINNESOTA112025
BayfieldWISCONSIN112025
Pleasant ValMICHIGAN101997
PickfordMICHIGAN92025
BemidjiMINNESOTA91980
Weirgor SpringsWISCONSIN92025
Walloon Lake 2MICHIGAN82024
MayfieldMICHIGAN82025
Lake CityMICHIGAN72022
OberlinMICHIGAN72024
HerronMICHIGAN72016
BackusMINNESOTA72025
Iron RiverWISCONSIN72025
BashawWISCONSIN72025
CathroMICHIGAN62016
Pine RiverMINNESOTA62025
LudeMINNESOTA62025
GreenbushMINNESOTA62025
Rib LakeWISCONSIN62025

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