BirdAnalyst
Species · BCR 11 · BBS 2026 Release · 1966–2025

Chimney Swift In Prairie Potholes

All regionsPrairie PotholesAerial insectivores

Chimney Swift in Prairie Potholes has fallen sharply: down 74% on the route-weighted index since 1969.

-74%Since 1969TrendPercent 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 →
70Routes 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 →

Chimney Swift has fallen sharply in Prairie Potholes: down 74% on the route-weighted index since 1969.

Chimney Swift In Prairie Potholes Population Forecast

If the recent trend holds, Chimney Swift in Prairie Potholes is projected to rise about 13% by 2030 — from 0.28 in 2025 to a central estimate of 0.32 (95% range 0.00–0.94). A 5-year backtest shows a typical error of ±35.1%, with 100% of held-out values landing inside the 95% band.

+13%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 →
0.32Projected 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 →
0.00–0.9495% 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 →
±35.1%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, Chimney Swift in Prairie Potholes is projected to rise about 13% by 2030 — from 0.28 in 2025 to a central estimate of 0.32 (95% range 0.00–0.94). A 5-year backtest shows a typical error of ±35.1%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.390.001.0
20270.370.000.99
20280.350.000.97
20290.340.000.95
20300.320.000.94

Routes In Prairie Potholes

Routes recording Chimney Swift in Prairie Potholes.
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 →
AbercrombieNORTH-DAKOTA82012
Abercrombie 2NORTH-DAKOTA72017
ArlingtonMINNESOTA52022
CourtlandMINNESOTA52025
MadisonNEBRASKA52018
ScrantonIOWA42010
ClareIOWA42019
BadgerMINNESOTA42015
HarlemMONTANA42021
TildenNEBRASKA42025
White LakeSOUTH-DAKOTA42000
PantherIOWA32023
ChandlerMINNESOTA32023
BeltramiMINNESOTA32007
Chokio NorthMINNESOTA32013
GlasgowMONTANA31982
Eagle CreekNEBRASKA32025
MidwayNEBRASKA32025
BroadlandSOUTH-DAKOTA32001
ForbesSOUTH-DAKOTA32024
MccallsburgIOWA22024
BurchinalIOWA22015
HartlandMINNESOTA22016
Redwood FallMINNESOTA22014
MaynardMINNESOTA22015

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