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Species · Maryland · BBS 2026 Release · 1966–2025

Magnolia Warbler Population Trend in Maryland

All statesForest birds

Magnolia Warbler in Maryland has surged: up 472% on the route-weighted index since 1968.

+472%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 →
8Routes 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 MarylandNotable 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 Maryland. See the full index history below.

Magnolia Warbler Population Forecast in Maryland

If the recent trend holds, Magnolia Warbler in Maryland is projected to fall about 22% by 2030 — from 0.29 in 2025 to a central estimate of 0.23 (95% range 0.13–0.33). A 5-year backtest shows a typical error of ±45%, with 80% of held-out values landing inside the 95% band.

-22%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 →
0.23Projected 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 →
0.13–0.3395% 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%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 Maryland is projected to fall about 22% by 2030 — from 0.29 in 2025 to a central estimate of 0.23 (95% range 0.13–0.33). A 5-year backtest shows a typical error of ±45%, with 80% 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 →
20260.210.110.31
20270.210.110.32
20280.220.120.32
20290.220.120.32
20300.230.130.33

Magnolia Warbler Survey Routes in Maryland

Routes recording Magnolia Warbler in Maryland.
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 →
Jennings520251995
Finzel320251996
Accident 2220252019
Floyd120251967
Mt Nebo119891969
Vindex120241966
Accident120151992
Steyer120191996

Magnolia Warbler Population Trend in Other States

connecticutmainemassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiopennsylvaniavermontvirginiawest-virginiawisconsin

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