BirdAnalyst
Species · BCR 12 · BBS 2025 Release · 1966–2024

Bank Swallow In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionAerial insectivores

Bank Swallow in Boreal Hardwood Transition has collapsed: down 92% on the route-weighted index since 1968.

-92%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 →
93Routes 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 →
58YearsYears 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 →

Bank Swallow has collapsed in Boreal Hardwood Transition: down 92% on the route-weighted index since 1968.

Bank Swallow In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Bank Swallow in Boreal Hardwood Transition is projected to fall about 51% by 2029 — from 0.19 in 2024 to a central estimate of 0.09 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±161.6%, with 100% of held-out values landing inside the 95% band.

-51%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 →
0.09Projected 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 →
0.00–1.895% 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 →
±161.6%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 Boreal Hardwood Transition is projected to fall about 51% by 2029 — from 0.19 in 2024 to a central estimate of 0.09 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±161.6%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.260.001.9
20260.210.001.9
20270.170.001.8
20280.130.001.8
20290.090.001.8

Routes In Boreal Hardwood Transition

Routes recording Bank 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 →
BerglandMICHIGAN411993
WilsonMICHIGAN402007
BenaMINNESOTA201967
IrmaWISCONSIN122000
HollisterWISCONSIN122012
CathroMICHIGAN102007
LudeMINNESOTA102016
BagleyMINNESOTA101995
BootjackMICHIGAN82009
CromwellMINNESOTA82022
NebishMINNESOTA81993
CavourWISCONSIN82009
BemidjiMINNESOTA71980
MahtowaMINNESOTA71993
OntonagonMICHIGAN61971
MareniscoMICHIGAN62003
Walloon Lake 2MICHIGAN62024
CouderayWISCONSIN62017
ExelandWISCONSIN62010
IshpemingMICHIGAN51991
CreightonMICHIGAN52019
SkeelsMICHIGAN52008
Red OakMICHIGAN51990
WaskishMINNESOTA51988
PickfordMICHIGAN42014

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