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Species · Wisconsin · BBS 2025 Release · 1966–2024

Northern Rough-winged Swallow Population Trend in Wisconsin

All statesAerial insectivores

Northern Rough-winged Swallow in Wisconsin has edged down: down 17% on the route-weighted index since 1968.

-17%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 →
91Routes 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 Northern Rough-winged Swallow 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 Northern Rough-winged Swallow in Wisconsin. See the full index history below.

Northern Rough-winged Swallow Population Forecast in Wisconsin

If the recent trend holds, Northern Rough-winged Swallow in Wisconsin is projected to rise about 144% by 2029 — from 0.57 in 2024 to a central estimate of 1.4 (95% range 0.31–2.5). A 5-year backtest shows a typical error of ±122%, with 40% of held-out values landing inside the 95% band.

+144%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 →
1.4Projected 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 →
0.31–2.595% 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 →
±122%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, Northern Rough-winged Swallow in Wisconsin is projected to rise about 144% by 2029 — from 0.57 in 2024 to a central estimate of 1.4 (95% range 0.31–2.5). A 5-year backtest shows a typical error of ±122%, with 40% 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 →
20251.40.342.5
20261.40.342.5
20271.40.332.5
20281.40.322.5
20291.40.312.5

Northern Rough-winged Swallow Survey Routes in Wisconsin

Routes recording Northern Rough-winged Swallow 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 →
Esdaile2220231966
Eagle River1820111971
Cochrane1420221966
Gilmanton1320221970
River Falls1220221998
Gilman920221969
Clintonville920181972
Annaton820241998
Hazel Green720181967
Verona620231991
Prairie Du Chien620241999
Kendall520221967
Pardeeville520211980
Fall River520241966
Highland520211999
Beloit520241998
Popple River420221969
Elderon419981967
New Lisbon420171967
Paris420241966
Omro 2420242002
Cavour420212000
Kiel420221998
Mukwonago420032000
Chaffey320151972

Northern Rough-winged Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawyoming

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