BirdAnalyst
Species · BCR 24 · BBS 2025 Release · 1966–2024

Chimney Swift In Central Hardwoods

All regionsCentral HardwoodsAerial insectivores

Chimney Swift in Central Hardwoods has collapsed: down 83% on the route-weighted index since 1968.

-83%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 →
162Routes 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 collapsed in Central Hardwoods: down 83% on the route-weighted index since 1968.

Chimney Swift In Central Hardwoods Population Forecast

If the recent trend holds, Chimney Swift in Central Hardwoods is projected to fall about 73% by 2029 — from 2.6 in 2024 to a central estimate of 0.70 (95% range 0.00–4.9). A 5-year backtest shows a typical error of ±18.4%, with 100% of held-out values landing inside the 95% band.

-73%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 →
0.70Projected 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 →
0.00–4.995% 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 →
±18.4%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 Central Hardwoods is projected to fall about 73% by 2029 — from 2.6 in 2024 to a central estimate of 0.70 (95% range 0.00–4.9). A 5-year backtest shows a typical error of ±18.4%, 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 →
20252.00.006.2
20261.70.005.9
20271.30.005.6
20281.00.005.2
20290.700.004.9

Routes In Central Hardwoods

Routes recording Chimney Swift in Central Hardwoods.
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 →
FarwellARKANSAS932018
MillionKENTUCKY501986
Cole CampMISSOURI441990
LeveeKENTUCKY301982
Daniel BooneKENTUCKY261988
GoshenKENTUCKY241999
Indian SpgsINDIANA192024
BoxvilleKENTUCKY191983
Buena VistaKENTUCKY192017
GlencoeKENTUCKY172018
SyracuseMISSOURI172023
Iron BridgeKENTUCKY161998
GraydonMISSOURI152022
EvansvilleINDIANA142019
DixieKENTUCKY122019
DixonKENTUCKY122022
CollinwoodTENNESSEE122024
GlenTENNESSEE112024
Valhermoso SpgsALABAMA102010
EastviewKENTUCKY102024
Levee 2KENTUCKY102019
RiverqueenKENTUCKY102024
HillsboroALABAMA91996
Ravenden SpringsARKANSAS92015
WashingtonINDIANA92024

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