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

Cliff Swallow In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionAerial insectivores

Cliff Swallow in Boreal Hardwood Transition has collapsed: down 93% on the route-weighted index since 1968.

-93%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 →
101Routes 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 →

Cliff Swallow has collapsed in Boreal Hardwood Transition: down 93% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Cliff Swallow in Boreal Hardwood Transition is projected to fall about 100% by 2029 — from 1.4 in 2024 to a central estimate of 0.00 (95% range 0.00–14). A 5-year backtest shows a typical error of ±345.1%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1495% 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 →
±345.1%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, Cliff Swallow in Boreal Hardwood Transition is projected to fall about 100% by 2029 — from 1.4 in 2024 to a central estimate of 0.00 (95% range 0.00–14). A 5-year backtest shows a typical error of ±345.1%, 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 →
20250.000.0014
20260.000.0014
20270.000.0014
20280.000.0014
20290.000.0014

Routes In Boreal Hardwood Transition

Routes recording Cliff 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 →
WaskishMINNESOTA402024
CrandonWISCONSIN202019
HermanMICHIGAN152015
RacoMICHIGAN152001
BenaMINNESOTA151977
Cass LakeMINNESOTA142011
Weirgor SpringsWISCONSIN132023
WarroadMINNESOTA122017
ShingletonMICHIGAN101990
ChaffeyWISCONSIN102013
Grand ViewWISCONSIN102010
ExelandWISCONSIN102022
MayfieldMICHIGAN92007
Island LakeMINNESOTA91995
Nett LakeMINNESOTA92018
Gibbs CityMICHIGAN81997
Maple GroveMICHIGAN82024
FloodwoodMINNESOTA82024
Sherry LakeMINNESOTA81997
GreenbushMINNESOTA82023
Ned LakeMICHIGAN72024
Pleasant ValMICHIGAN71991
Wigwam BayMINNESOTA72023
BemidjiMINNESOTA71968
BrainerdMINNESOTA62024

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