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

Red-winged Blackbird Population Trend in Maryland

All statesGeneralists

Red-winged Blackbird in Maryland has declined: down 47% on the route-weighted index since 1968.

-47%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 →
76Routes 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 Red-winged Blackbird 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 Red-winged Blackbird in Maryland. See the full index history below.

Red-winged Blackbird Population Forecast in Maryland

If the recent trend holds, Red-winged Blackbird in Maryland is projected to fall about 29% by 2029 — from 40 in 2024 to a central estimate of 28 (95% range 14–42). A 5-year backtest shows a typical error of ±29.6%, with 80% of held-out values landing inside the 95% band.

-29%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 →
28Projected 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 →
14–4295% 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 →
±29.6%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, Red-winged Blackbird in Maryland is projected to fall about 29% by 2029 — from 40 in 2024 to a central estimate of 28 (95% range 14–42). A 5-year backtest shows a typical error of ±29.6%, with 80% 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 →
2025311645
2026301644
2027291544
2028291443
2029281442

Red-winged Blackbird Survey Routes in Maryland

Routes recording Red-winged Blackbird 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 →
Honga20020241966
Madison15620241966
Grove Neck11119961992
Melitota10720241966
Cokesbury10320241966
Emmitsburg9620241966
Easton9220211966
Piney Neck8520241966
Jennings8020241995
Bachman Mill6720241966
Golden Hill6520241966
Williamsport5920241966
Matthews5820241966
Earlton5820242014
Harmony5520171966
Millington5020241966
Mt Nebo4919911969
Olney4820241966
Pleasant Val4520241966
Furnace Town3820242015
Forest Grove3620232011
Wolfsville3520241966
Finzel3520241995
Ijamsville3420241986
Fruitland3319981966

Red-winged Blackbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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