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

Blackburnian Warbler Population Trend in Wisconsin

All statesForest birds

Blackburnian Warbler in Wisconsin has surged: up 168% on the route-weighted index since 1968.

+168%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 →
38Routes 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 Blackburnian Warbler 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 →

long arc increasecomputed 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 →

Blackburnian Warbler has surged in Wisconsin: up 168% on the route-weighted index since 1968.

Blackburnian Warbler Population Forecast in Wisconsin

If the recent trend holds, Blackburnian Warbler in Wisconsin is projected to stay roughly flat through 2029, near 0.92 (95% range 0.53–1.3). A 5-year backtest shows a typical error of ±29.6%, with 60% of held-out values landing inside the 95% band.

+4%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 →
0.92Projected 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 →
0.53–1.395% 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 →
±29.6%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, Blackburnian Warbler in Wisconsin is projected to stay roughly flat through 2029, near 0.92 (95% range 0.53–1.3). A 5-year backtest shows a typical error of ±29.6%, with 60% 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 →
20250.880.491.3
20260.890.501.3
20270.900.511.3
20280.910.521.3
20290.920.531.3

Blackburnian Warbler Survey Routes in Wisconsin

Routes recording Blackburnian Warbler 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 →
Land O Lakes1020161967
Eagle River1020241966
Cavour920241998
Popple River820241967
Mellen620241998
Land O' Lakes 2620242017
Pigeon Creek520192007
Grand View420241966
Shanagolden420241966
Rib Lake420241970
Mcnaughton420241967
Gresham420241999
Wausaukee320221981
Washington I320241967
Iron River220241967
Montreal220241975
Exeland220231969
Phillips220151970
Crandon220241967
Weirgor Springs220232011
Flambeau220231998
Chaffey120211966
Minong120191974
Bayfield120241973
Union Twp120131975

Blackburnian Warbler Population Trend in Other States

connecticutgeorgiaindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiopennsylvaniarhode-islandtennesseevermontvirginiawest-virginia

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