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Species · Maryland · BBS 2025 Release · 1966–2024

Grasshopper Sparrow Population Trend in Maryland

All statesGrassland birds

Grasshopper Sparrow in Maryland has fallen sharply: down 60% on the route-weighted index since 1968.

-60%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 →
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 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 60% 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 16% by 2029 — from 3.3 in 2024 to a central estimate of 2.8 (95% range 0.09–5.5). A 5-year backtest shows a typical error of ±23.6%, with 100% of held-out values landing inside the 95% band.

-16%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 →
2.8Projected 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 →
0.09–5.595% 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 →
±23.6%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 16% by 2029 — from 3.3 in 2024 to a central estimate of 2.8 (95% range 0.09–5.5). A 5-year backtest shows a typical error of ±23.6%, 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 →
20253.00.245.7
20262.90.205.6
20272.90.175.6
20282.80.135.6
20292.80.095.5

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
Emmitsburg2620241966
Cokesbury2320241966
Smithsburg1420141968
Millington1320241966
Easton1120211966
Mardela1020191966
Newark1020241966
Madonna920222009
Williamsport820241966
Walnut620242006
Pt Republic619891966
Hughesville620241966
Piney Neck520241966
Honga520241966
Ijamsville520241986
Pr Frederick520241991
Eklo420181966
Tall Timbers420141966
Melitota420241966
Forest Grove420232011
Wheaton419951990
Warfieldsbrg320241966
Pleasant Val320191966
La Plata320091966

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 2026-05-22.