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

Worm-eating Warbler Population Trend in Missouri

All statesForest birds

Worm-eating Warbler in Missouri has surged: up 204% on the route-weighted index since 1976.

+204%Since 1976TrendPercent 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 →
36Routes 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 →
48YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Worm-eating Warbler Trends in MissouriNotable 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 →

Worm-eating Warbler has surged in Missouri: up 204% on the route-weighted index since 1976.

Worm-eating Warbler Population Forecast in Missouri

If the recent trend holds, Worm-eating Warbler in Missouri is projected to rise about 250% by 2029 — from 0.15 in 2024 to a central estimate of 0.52 (95% range 0.06–0.98). A 5-year backtest shows a typical error of ±235.4%, with 60% of held-out values landing inside the 95% band.

+250%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 →
0.52Projected 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 →
0.06–0.9895% 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 →
±235.4%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, Worm-eating Warbler in Missouri is projected to rise about 250% by 2029 — from 0.15 in 2024 to a central estimate of 0.52 (95% range 0.06–0.98). A 5-year backtest shows a typical error of ±235.4%, with 60% of held-out values landing inside the 95% band.19732029
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 →
20250.500.040.96
20260.500.040.97
20270.510.050.97
20280.520.060.98
20290.520.060.98

Worm-eating Warbler Survey Routes in Missouri

Routes recording Worm-eating Warbler in Missouri.
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 →
Clementine519961985
Cascade420231978
Ironton319801973
Deventer219841984
Emden220192018
House Springs220242024
Clementine 2220072005
Pulaski119971997
Sweden120142007
Pineville119951986
Akers120241992
Wesco120231973
Handley120121985
Woodlandville120242024
Hayden120071996
Danville120092009
Syracuse120132013
Ohio120061982
Gerald120212014
Huntsville120191989
Viburnum120242017
Doe Run120232016
Kahoka119861986
Williamsvill120241994
Bennett120241994

Worm-eating Warbler Population Trend in Other States

alabamaarkansasconnecticutdelawaregeorgiaillinoisindianaiowakentuckylouisianamarylandmassachusettsmississippinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvirginiawest-virginiawisconsin

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