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Species · Massachusetts · BBS 2025 Release · 1966–2024

Magnolia Warbler Population Trend in Massachusetts

All statesForest birds

Magnolia Warbler in Massachusetts has declined: down 49% on the route-weighted index since 1970.

-49%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 →
17Routes 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 →
56YearsYears 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 MassachusettsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Magnolia Warbler in Massachusetts. See the full index history below.

Magnolia Warbler Population Forecast in Massachusetts

If the recent trend holds, Magnolia Warbler in Massachusetts is projected to rise about 28% by 2029 — from 0.27 in 2024 to a central estimate of 0.34 (95% range 0.00–0.71). A 5-year backtest shows a typical error of ±315.8%, with 60% of held-out values landing inside the 95% band.

+28%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 →
0.34Projected 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 →
0.00–0.7195% 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 →
±315.8%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, Magnolia Warbler in Massachusetts is projected to rise about 28% by 2029 — from 0.27 in 2024 to a central estimate of 0.34 (95% range 0.00–0.71). A 5-year backtest shows a typical error of ±315.8%, with 60% of held-out values landing inside the 95% band.19672029
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 →
20250.340.000.71
20260.340.000.71
20270.340.000.71
20280.340.000.71
20290.340.000.71

Magnolia Warbler Survey Routes in Massachusetts

Routes recording Magnolia Warbler in Massachusetts.
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 →
Cummington520141969
Cummington 2220242015
Ware River120121994
Mansfield120022002
Princeton119761970
E Pepperell119671967
Belchertown120241974
Warren120021981
S Barre119861971
N Orange120191969
Chesterfield120241969
Cheshire119861973
Pittsfield120161989
Sheffield120131979
Monterey120192019
Holden120022002
Hancock120152009

Magnolia Warbler Population Trend in Other States

connecticutmainemarylandmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiopennsylvaniavermontvirginiawest-virginiawisconsin

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