BirdAnalyst
Species · BCR 28 · BBS 2025 Release · 1966–2024

Swainson's Warbler In Appalachian Mountains

All regionsAppalachian MountainsForest birds

Swainson's Warbler in Appalachian Mountains has surged: up 20× on the route-weighted index since 1971.

20×Since 1971TrendPercent 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 →
68Routes 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 →
55YearsYears 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 →

Swainson's Warbler has surged in Appalachian Mountains: up 20× on the route-weighted index since 1971.

Swainson's Warbler In Appalachian Mountains Population Forecast

If the recent trend holds, Swainson's Warbler in Appalachian Mountains is projected to fall about 44% by 2029 — from 0.30 in 2024 to a central estimate of 0.17 (95% range 0.08–0.25). A 5-year backtest shows a typical error of ±60.2%, with 0% of held-out values landing inside the 95% band.

-44%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 →
0.17Projected 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 →
0.08–0.2595% 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 →
±60.2%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, Swainson's Warbler in Appalachian Mountains is projected to fall about 44% by 2029 — from 0.30 in 2024 to a central estimate of 0.17 (95% range 0.08–0.25). A 5-year backtest shows a typical error of ±60.2%, with 0% of held-out values landing inside the 95% band.19692029
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 →
20250.150.070.24
20260.160.070.24
20270.160.070.25
20280.160.070.25
20290.170.080.25

Routes In Appalachian Mountains

Routes recording Swainson's Warbler in Appalachian Mountains.
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 →
FontanaNORTH-CAROLINA72024
HighlandsNORTH-CAROLINA62024
TellicoTENNESSEE62024
GreensportALABAMA52024
HanoverWEST-VIRGINIA52024
Smokey JctTENNESSEE42022
Willis SprngTENNESSEE42023
Strange CrkWEST-VIRGINIA42024
DrummondALABAMA32022
Mountain CtyGEORGIA32024
BrevardNORTH-CAROLINA32024
McfarlandTENNESSEE31976
Pine Mtn.VIRGINIA32024
YawkeyWEST-VIRGINIA32024
Sunny EveALABAMA22022
Mt OliveALABAMA22024
KymulgaALABAMA22024
RiversideALABAMA22013
Beattyville 2KENTUCKY22023
CullowheeNORTH-CAROLINA22024
OteenNORTH-CAROLINA22023
MurphyNORTH-CAROLINA22024
French Broad RiverNORTH-CAROLINA22024
WatervilleNORTH-CAROLINA22022
Table RockNORTH-CAROLINA22022

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