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

Swamp Sparrow Population Trend in Wisconsin

All statesGeneralists

Swamp Sparrow in Wisconsin has increased: up 37% on the route-weighted index since 1968.

+37%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 →
92Routes 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 Swamp Sparrow Trends in WisconsinNotable 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 Wisconsin. See the full index history below.

Swamp Sparrow Population Forecast in Wisconsin

If the recent trend holds, Swamp Sparrow in Wisconsin is projected to stay roughly flat through 2029, near 2.3 (95% range 1.5–3.0). A 5-year backtest shows a typical error of ±24.4%, with 80% of held-out values landing inside the 95% band.

+10%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 →
2.3Projected 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 →
1.5–3.095% 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 →
±24.4%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 Wisconsin is projected to stay roughly flat through 2029, near 2.3 (95% range 1.5–3.0). A 5-year backtest shows a typical error of ±24.4%, 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 →
20252.31.53.0
20262.31.53.0
20272.31.53.0
20282.31.53.0
20292.31.53.0

Swamp Sparrow Survey Routes in Wisconsin

Routes recording Swamp Sparrow in Wisconsin.
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 →
Gilman1420241966
Omro 21420242002
Mather1320231966
Briggsville1120241999
Flambeau1020241998
Cumberland920241966
Fall River720241967
Couderay620191973
Eden620241966
Amberg520241980
Gilmanton519881977
Unity520241970
Clintonville520241970
Pardeeville520241967
Mount Horeb519901967
Hebron520241966
Land O' Lakes 2520242017
Kiel520221998
Bayfield420241971
Shanagolden420241969
Holway419891967
Rib Lake420241967
Omro420011966
Verona420221991
Gresham420242006

Swamp Sparrow Population Trend in Other States

connecticutdelawareillinoisindianaiowamainemarylandmassachusettsmichiganminnesotanebraskanew-hampshirenew-jerseynew-yorknorth-dakotaohiopennsylvaniarhode-islandsouth-dakotavermontvirginiawest-virginia

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