BirdAnalyst
Species · Texas · BBS 2025 Release · 1966–2024

Swainson's Warbler Population Trend in Texas

All statesForest birds

Swainson's Warbler in Texas has surged: up 322% on the route-weighted index since 1974.

+322%Since 1974TrendPercent 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 →
29Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
45YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Swainson's Warbler Trends in TexasNotable 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 Texas: up 322% on the route-weighted index since 1974.

Swainson's Warbler Population Forecast in Texas

If the recent trend holds, Swainson's Warbler in Texas is projected to fall about 30% by 2029 — from 0.21 in 2024 to a central estimate of 0.15 (95% range 0.02–0.27). A 5-year backtest shows a typical error of ±40.2%, with 100% of held-out values landing inside the 95% band.

-30%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 →
0.15Projected 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 →
0.02–0.2795% 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 →
±40.2%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 Texas is projected to fall about 30% by 2029 — from 0.21 in 2024 to a central estimate of 0.15 (95% range 0.02–0.27). A 5-year backtest shows a typical error of ±40.2%, with 100% 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 →
20250.140.010.26
20260.140.010.27
20270.140.020.27
20280.140.020.27
20290.150.020.27

Swainson's Warbler Survey Routes in Texas

Routes recording Swainson's Warbler in Texas.
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 →
Big Sandy Bith520242015
Diboll520241975
Fred520241995
Hearne320241999
Town Bluff320241994
Athens320232015
Bon Wier320241996
Lance Rosier Bith220192014
Easton219941994
Oak Grove 2120112011
Paige120242024
Cayuga120242024
Chandler 2120092009
Livingston120241970
New Waverly120071969
Gause119971996
Caledonia120241993
Powell Park 2120242024
Morton120101974
Crossroads120242005
Easton 2120242024
Union Hill120231994
Alexander St120241995
Powell Park120101997
Weches120171998

Swainson's Warbler Population Trend in Other States

alabamaarkansasfloridageorgiakentuckylouisianamarylandmississippinorth-carolinaoklahomasouth-carolinatennesseevirginiawest-virginia

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