BirdAnalyst
Species · Vermont · BBS 2026 Release · 1966–2025

Magnolia Warbler Population Trend in Vermont

All statesForest birds

Magnolia Warbler in Vermont has surged: up 200% on the route-weighted index since 1968.

+200%Since 1968TrendPercent 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 →
24Routes 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 →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Magnolia Warbler Trends in VermontNotable 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 →

Magnolia Warbler has surged in Vermont: up 200% on the route-weighted index since 1968.

Magnolia Warbler Population Forecast in Vermont

If the recent trend holds, Magnolia Warbler in Vermont is projected to stay roughly flat through 2030, near 1.6 (95% range 0.23–2.9). A 5-year backtest shows a typical error of ±48.5%, with 100% of held-out values landing inside the 95% band.

+1%Change by 2030TrendPercent 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 →
1.6Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.23–2.995% 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 →
±48.5%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, Magnolia Warbler in Vermont is projected to stay roughly flat through 2030, near 1.6 (95% range 0.23–2.9). A 5-year backtest shows a typical error of ±48.5%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20261.60.232.9
20271.60.232.9
20281.60.232.9
20291.60.232.9
20301.60.232.9

Magnolia Warbler Survey Routes in Vermont

Routes recording Magnolia Warbler in Vermont.
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 →
Stratton720251967
Newbury 2520232005
Landgrove420251966
St Johnsbury420251970
Hardwick420241973
Greensboro420251967
Post Mills319941967
East Haven320251968
Middlesex220251968
Stowe220221988
Marlboro120251986
North Pownal119671967
S Reading120091968
Gaysville120001978
Shaftsbury120151977
S Wallingfrd120001976
W Rutland120171992
Northfld Fls120251980
East Calais120251967
Newbury120041987
Fletcher120251983
Waterville119801980
Hinesburg119781970
Grand Isle119931993

Magnolia Warbler Population Trend in Other States

connecticutmainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiopennsylvaniavirginiawest-virginiawisconsin

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.