BirdAnalyst
Species · BCR 4 · BBS 2025 Release · 1966–2024

Bank Swallow In BCR 4

All regionsBCR 4Aerial insectivores

Bank Swallow in BCR 4 has collapsed: down 79% on the route-weighted index since 1976.

-79%Since 1976TrendPercent 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 →
57Routes 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 →
46YearsYears 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 BCR 4: down 79% on the route-weighted index since 1976.

Bank Swallow In BCR 4 Population Forecast

If the recent trend holds, Bank Swallow in BCR 4 is projected to fall about 100% by 2029 — from 2.8 in 2024 to a central estimate of 0.00 (95% range 0.00–12). A 5-year backtest shows a typical error of ±117.5%, 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 →
0.00–1295% 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 →
±117.5%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, Bank Swallow in BCR 4 is projected to fall about 100% by 2029 — from 2.8 in 2024 to a central estimate of 0.00 (95% range 0.00–12). A 5-year backtest shows a typical error of ±117.5%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.110.0012
20260.000.0012
20270.000.0012
20280.000.0012
20290.000.0012

Routes In BCR 4

Routes recording Bank Swallow in BCR 4.
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 →
Bear CreekALASKA961991
WasillaALASKA651983
Kobuk River (Short)ALASKA561992
Koyukuk Riv.ALASKA422001
CircleALASKA312024
McgrathALASKA272019
Tangle LakesALASKA231987
Mud RiverALASKA202024
Hather CreekALASKA172022
Paxson LakeALASKA161992
CantwellALASKA112003
MatanuskaALASKA111983
Lake LouiseALASKA112008
Anvik RiverALASKA102024
MaclarenALASKA92024
KachemakALASKA82008
Porcupine R.ALASKA82002
DeltaALASKA82024
Goose BayALASKA71982
KalifonskyALASKA72016
Kanuti CanynALASKA72024
LivengoodALASKA62012
ChistochinaALASKA62024
HomerALASKA61982
Burma RoadALASKA62004

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