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Species · Maryland · BBS 2025 Release · 1966–2024

Hooded Warbler Population Trend in Maryland

All statesForest birds

Hooded Warbler in Maryland has surged: up 241% on the route-weighted index since 1968.

+241%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 →
54Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Hooded 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 →

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 →

Hooded Warbler has surged in Maryland: up 241% on the route-weighted index since 1968.

Hooded Warbler Population Forecast in Maryland

If the recent trend holds, Hooded Warbler in Maryland is projected to rise about 35% by 2029 — from 1.1 in 2024 to a central estimate of 1.5 (95% range 1.0–2.0). A 5-year backtest shows a typical error of ±29.3%, with 100% of held-out values landing inside the 95% band.

+35%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 →
1.5Projected 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 →
1.0–2.095% 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 →
±29.3%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, Hooded Warbler in Maryland is projected to rise about 35% by 2029 — from 1.1 in 2024 to a central estimate of 1.5 (95% range 1.0–2.0). A 5-year backtest shows a typical error of ±29.3%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20251.40.951.9
20261.50.972.0
20271.50.982.0
20281.51.02.0
20291.51.02.0

Hooded Warbler Survey Routes in Maryland

Routes recording Hooded 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 →
Oldtown1220241970
Finzel1020241995
Island Creek620241991
Pt Republic419891966
La Plata420091966
Hughesville420221966
Golden Hill419691969
Green Ridge420241995
Wolfsville320241966
Cheltenham320031969
Jennings320241995
Piney Grove320241996
Pr Frederick320231991
Vindex220181967
Smithsburg220141972
Berlin220111980
Pomonkey220241966
Pomfret220231967
Theodore220061969
Newark219981968
Floyd120221967
Mt Nebo119911976
Potomac Park119911973
Emmitsburg120212021
Olney120221974

Hooded Warbler Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianakentuckylouisianamassachusettsmichiganmississippimissourinew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvirginiawest-virginiawisconsin

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