BirdAnalyst
Species · New Hampshire · BBS 2026 Release · 1966–2025

Red-winged Blackbird Population Trend in New Hampshire

All statesWetland birds

Red-winged Blackbird in New Hampshire has fallen sharply: down 52% on the route-weighted index since 1968.

-52%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 →
26Routes 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 Red-winged Blackbird Trends in New HampshireNotable 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 declinecomputed 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 →

Red-winged Blackbird has fallen sharply in New Hampshire: down 52% on the route-weighted index since 1968.

Red-winged Blackbird Population Forecast in New Hampshire

If the recent trend holds, Red-winged Blackbird in New Hampshire is projected to fall about 32% by 2030 — from 14 in 2025 to a central estimate of 9.6 (95% range 2.7–16). A 5-year backtest shows a typical error of ±21.2%, with 100% of held-out values landing inside the 95% band.

-32%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 →
9.6Projected 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 →
2.7–1695% 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 →
±21.2%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 New Hampshire is projected to fall about 32% by 2030 — from 14 in 2025 to a central estimate of 9.6 (95% range 2.7–16). A 5-year backtest shows a typical error of ±21.2%, 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 →
2026114.018
2027113.617
2028103.317
20299.93.017
20309.62.716

Red-winged Blackbird Survey Routes in New Hampshire

Routes recording Red-winged Blackbird in New Hampshire.
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 →
Epsom3520251966
Dover3420251966
Dixvil Notch2920171966
Dixville Notch 22820252018
Canterbury2620251966
Marlow2120251966
Stratford2020251966
Fitzwilliam1820251966
East Kingston1820251999
Concord1720251966
Walpole1520251966
Wilmot1220251966
Lempster1220251966
Brentwood1119981966
Crawford Not1019751966
Clarksville1020251966
Peterborough920251966
Strafford920251966
Mt Chocorua720251967
Glen720251975
Milan620251966
Hopkinton520251966
Jefferson Hl420251966
Jeffers Ntch420251993
Gilmantn I W320251969

Red-winged Blackbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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