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

Tree Swallow In Central Hardwoods

All regionsCentral HardwoodsAerial insectivores

Tree Swallow in Central Hardwoods has surged: up 37× on the route-weighted index since 1978.

37×Since 1978TrendPercent 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 →
125Routes 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 increasecomputed 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 →

Tree Swallow has surged in Central Hardwoods: up 37× on the route-weighted index since 1978.

Tree Swallow In Central Hardwoods Population Forecast

If the recent trend holds, Tree Swallow in Central Hardwoods is projected to rise about 13% by 2029 — from 1.7 in 2024 to a central estimate of 2.0 (95% range 1.1–2.8). A 5-year backtest shows a typical error of ±27.5%, with 80% of held-out values landing inside the 95% band.

+13%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 →
2.0Projected 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 →
1.1–2.895% 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 →
±27.5%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, Tree Swallow in Central Hardwoods is projected to rise about 13% by 2029 — from 1.7 in 2024 to a central estimate of 2.0 (95% range 1.1–2.8). A 5-year backtest shows a typical error of ±27.5%, with 80% of held-out values landing inside the 95% band.19712029
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 →
20251.80.972.6
20261.81.02.6
20271.91.12.7
20281.91.12.7
20292.01.12.8

Routes In Central Hardwoods

Routes recording Tree Swallow 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 →
NewberryINDIANA202024
Brnt PrairieILLINOIS172024
BelmontINDIANA152021
EastviewKENTUCKY122024
GlencoeKENTUCKY122018
Cross PlainsINDIANA112024
CyprssINDIANA112019
DixonKENTUCKY112024
EugeneMISSOURI102024
PleasurevillKENTUCKY92024
GranitevilleMISSOURI92018
McbrayerKENTUCKY82022
Wheeler DamALABAMA72023
PimentoINDIANA62024
SpencerINDIANA62024
MillersburgINDIANA62024
CelestineINDIANA62024
Cedar GroveKENTUCKY62024
Lebanon JunctionKENTUCKY62023
Belotes BendTENNESSEE62018
PeytonsvilleTENNESSEE62024
KarnakILLINOIS52024
CumbackINDIANA52017
HegiraKENTUCKY52023
Sewell ShopKENTUCKY52022

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