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Species · Maryland · BBS 2026 Release · 1966–2025

Grasshopper Sparrow Population Trend in Maryland

All statesGrassland birds

Grasshopper Sparrow in Maryland has fallen sharply: down 59% on the route-weighted index since 1968.

-59%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 →
71Routes 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 Grasshopper Sparrow 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 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 →

Grasshopper Sparrow has fallen sharply in Maryland: down 59% on the route-weighted index since 1968.

Grasshopper Sparrow Population Forecast in Maryland

If the recent trend holds, Grasshopper Sparrow in Maryland is projected to fall about 28% by 2030 — from 3.9 in 2025 to a central estimate of 2.8 (95% range 0.14–5.5). A 5-year backtest shows a typical error of ±25.6%, with 100% of held-out values landing inside the 95% band.

-28%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 →
2.8Projected 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 →
0.14–5.595% 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 →
±25.6%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, Grasshopper Sparrow in Maryland is projected to fall about 28% by 2030 — from 3.9 in 2025 to a central estimate of 2.8 (95% range 0.14–5.5). A 5-year backtest shows a typical error of ±25.6%, 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 →
20263.00.295.7
20273.00.255.7
20282.90.215.6
20292.90.185.6
20302.80.145.5

Grasshopper Sparrow Survey Routes in Maryland

Routes recording Grasshopper Sparrow 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 →
Harmony4620171966
Cokesbury1920251966
Honga1720251966
Williamsport1420251966
Smithsburg1420141968
Emmitsburg1320251966
Newark1220251966
Mardela1020191966
Madonna920222009
Golden Hill820251966
Berlin720251981
Ijamsville720251986
Warfieldsbrg620251966
Walnut620242006
Pt Republic619891966
Olney520251966
Millington520251966
Eklo420181966
Tall Timbers420141966
Hughesville420251966
Piney Neck420251966
Easton420251966
Forest Grove420232011
Furnace Town420252015
Wheaton419951990

Grasshopper Sparrow Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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