BirdAnalyst
Species · BCR 11 · BBS 2025 Release · 1966–2024

Chimney Swift In Prairie Potholes

All regionsPrairie PotholesAerial insectivores

Chimney Swift in Prairie Potholes has fallen sharply: down 71% on the route-weighted index since 1969.

-71%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 →
57YearsYears 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 71% 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 stay roughly flat through 2029, near 0.35 (95% range 0.00–0.97). A 5-year backtest shows a typical error of ±23.1%, with 100% of held-out values landing inside the 95% band.

-4%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 →
0.35Projected 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 →
0.00–0.9795% 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 →
±23.1%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 stay roughly flat through 2029, near 0.35 (95% range 0.00–0.97). A 5-year backtest shows a typical error of ±23.1%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.420.001.0
20260.400.001.0
20270.380.001.0
20280.370.000.99
20290.350.000.97

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 →
CourtlandMINNESOTA122024
TildenNEBRASKA82023
AbercrombieNORTH-DAKOTA82012
Abercrombie 2NORTH-DAKOTA72017
MidwayNEBRASKA62023
ArlingtonMINNESOTA52022
MadisonNEBRASKA52018
ScrantonIOWA42010
ClareIOWA42019
BadgerMINNESOTA42015
HarlemMONTANA42021
White LakeSOUTH-DAKOTA42000
PantherIOWA32023
ChandlerMINNESOTA32023
BeltramiMINNESOTA32007
Chokio NorthMINNESOTA32013
GlasgowMONTANA31982
Eagle CreekNEBRASKA32024
BroadlandSOUTH-DAKOTA32001
ForbesSOUTH-DAKOTA32024
MccallsburgIOWA22024
BurchinalIOWA22015
HartlandMINNESOTA22016
Redwood FallMINNESOTA22014
MaynardMINNESOTA22015

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