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

Cliff Swallow Population Trend in Wisconsin

All statesAerial insectivores

Cliff Swallow in Wisconsin has edged down: down 21% on the route-weighted index since 1968.

-21%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 →
94Routes 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 Cliff 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 Cliff Swallow in Wisconsin. See the full index history below.

Cliff Swallow Population Forecast in Wisconsin

If the recent trend holds, Cliff Swallow in Wisconsin is projected to fall about 31% by 2029 — from 8.1 in 2024 to a central estimate of 5.6 (95% range 0.00–17). A 5-year backtest shows a typical error of ±47.3%, with 100% of held-out values landing inside the 95% band.

-31%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 →
5.6Projected 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 →
0.00–1795% 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 →
±47.3%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, Cliff Swallow in Wisconsin is projected to fall about 31% by 2029 — from 8.1 in 2024 to a central estimate of 5.6 (95% range 0.00–17). A 5-year backtest shows a typical error of ±47.3%, 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 →
20256.50.0018
20266.30.0018
20276.00.0018
20285.80.0017
20295.60.0017

Cliff Swallow Survey Routes in Wisconsin

Routes recording Cliff 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 →
Kendall32620231967
N Andover6020241967
Kiel6020221998
Trempealeau5420241967
Omro 25020242002
Hazel Green4920241966
Clintonville4520241967
Esdaile4120241972
New Lisbon4120241967
Wiota4120241966
Newburg Crns3620241974
Mather3520231969
Holway3419881967
Hudson2320241967
Loraine2220211966
Crandon2020191967
Casco2020241966
Gresham2020241998
Annaton1820241998
Stevens Pt1620141966
Weyerhauser1520241966
Manitowoc1520241967
Viroqua1420241979
N Freedom1420241966
Weirgor Springs1320232007

Cliff Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawyoming

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