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

Swamp Sparrow Population Trend in Maryland

All statesGeneralists

Swamp Sparrow in Maryland has increased: up 40% on the route-weighted index since 1969.

+40%Since 1969TrendPercent 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 →
16Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Swamp 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 →

No notable trend signals for Swamp Sparrow in Maryland. See the full index history below.

Swamp Sparrow Population Forecast in Maryland

If the recent trend holds, Swamp Sparrow in Maryland is projected to stay roughly flat through 2029, near 0.07 (95% range 0.00–0.17). A 5-year backtest shows a typical error of ±71.3%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.07Projected 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 →
0.00–0.1795% 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 →
±71.3%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, Swamp Sparrow in Maryland is projected to stay roughly flat through 2029, near 0.07 (95% range 0.00–0.17). A 5-year backtest shows a typical error of ±71.3%, 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 →
20250.080.000.18
20260.070.000.17
20270.070.000.17
20280.070.000.17
20290.070.000.17

Swamp Sparrow Survey Routes in Maryland

Routes recording Swamp 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 →
Mt Nebo319911970
Jennings320232012
Melitota219841983
Floyd120221966
Vindex120221968
Harmony120012001
Smithsburg119971997
Accident120141992
Accident 2120232023
Madison120142014
Pleasant Val119821982
Cokesbury120242006
Eklo119981995
Upper Xrds119951995
Steyer120161996
Finzel120182004

Swamp Sparrow Population Trend in Other States

connecticutdelawareillinoisindianaiowamainemassachusettsmichiganminnesotanebraskanew-hampshirenew-jerseynew-yorknorth-dakotaohiopennsylvaniarhode-islandsouth-dakotavermontvirginiawest-virginiawisconsin

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