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Species · BCR 25 · BBS 2025 Release · 1966–2024

Swainson's Warbler In West Gulf Coastal Plain / Ouachitas

All regionsWest Gulf Coastal Plain / OuachitasForest birds

Swainson's Warbler in West Gulf Coastal Plain / Ouachitas has surged: up 748% on the route-weighted index since 1970.

+748%Since 1970TrendPercent 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 →
65Routes 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 →
52YearsYears 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 West Gulf Coastal Plain / Ouachitas: up 748% on the route-weighted index since 1970.

Swainson's Warbler In West Gulf Coastal Plain / Ouachitas Population Forecast

If the recent trend holds, Swainson's Warbler in West Gulf Coastal Plain / Ouachitas is projected to fall about 32% by 2029 — from 1.3 in 2024 to a central estimate of 0.85 (95% range 0.42–1.3). A 5-year backtest shows a typical error of ±45.8%, with 20% of held-out values landing inside the 95% band.

-32%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 →
0.85Projected 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 →
0.42–1.395% 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 →
±45.8%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 West Gulf Coastal Plain / Ouachitas is projected to fall about 32% by 2029 — from 1.3 in 2024 to a central estimate of 0.85 (95% range 0.42–1.3). A 5-year backtest shows a typical error of ±45.8%, with 20% of held-out values landing inside the 95% band.19682029
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 →
20250.790.361.2
20260.810.381.2
20270.820.391.3
20280.840.411.3
20290.850.421.3

Routes In West Gulf Coastal Plain / Ouachitas

Routes recording Swainson's Warbler in West Gulf Coastal Plain / Ouachitas.
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 →
Lake CoveLOUISIANA82017
TroutLOUISIANA62024
HargisLOUISIANA62010
GoodwillLOUISIANA52024
GraysonLOUISIANA52021
DibollTEXAS52024
FredTEXAS52024
Big Sandy BithTEXAS52024
LongstreetLOUISIANA42021
Flat CreekLOUISIANA42024
WomackLOUISIANA42024
Burr FerryLOUISIANA42024
ClayLOUISIANA32024
Mount UnionLOUISIANA32023
EnterpriseLOUISIANA32024
Town BluffTEXAS32024
AthensTEXAS32023
Bon WierTEXAS32024
De RidderLOUISIANA22019
LinvilleLOUISIANA22023
EvelynLOUISIANA22024
EastonTEXAS21994
Lance Rosier BithTEXAS22019
Old MiloARKANSAS12024
RamseyARKANSAS11994

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