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Species · Minnesota · BBS 2026 Release · 1966–2025

Chestnut-sided Warbler Population Trend in Minnesota

All statesForest birds

Chestnut-sided Warbler in Minnesota has increased: up 41% on the route-weighted index since 1969.

+41%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 →
56Routes 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 Chestnut-sided Warbler Trends in MinnesotaNotable 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 Chestnut-sided Warbler in Minnesota. See the full index history below.

Chestnut-sided Warbler Population Forecast in Minnesota

If the recent trend holds, Chestnut-sided Warbler in Minnesota is projected to fall about 18% by 2030 — from 9.5 in 2025 to a central estimate of 7.8 (95% range 4.1–11). A 5-year backtest shows a typical error of ±36%, with 60% of held-out values landing inside the 95% band.

-18%Change by 2030TrendPercent 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 →
7.8Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
4.1–1195% 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 →
±36%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, Chestnut-sided Warbler in Minnesota is projected to fall about 18% by 2030 — from 9.5 in 2025 to a central estimate of 7.8 (95% range 4.1–11). A 5-year backtest shows a typical error of ±36%, with 60% of held-out values landing inside the 95% band.19672030
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 →
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Chestnut-sided Warbler Survey Routes in Minnesota

Routes recording Chestnut-sided Warbler in Minnesota.
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 →
Sherry Lake6420221969
Chisholm6220242019
Hart Lake6120251967
Sawbill Lndg5020251973
Crane Lake4920251969
Lockport4620251967
Jordan4120251993
Glendale3820251993
Bigfork3420251993
Blackduck3220222004
Bena2519771967
Cass Lake2420161980
Cromwell2320251967
Nebish2120251982
Tamarac Nwr2020241991
Nett Lake2020242013
Babbitt2020251994
Hovland1920251973
Greenbush1820251993
Mahtowa1620231993
Cohasset1520221973
Sawbill Camp1520251993
Lude1220251979
Evergreen1120251970
Debs1120251969

Chestnut-sided Warbler Population Trend in Other States

alabamaarkansascoloradoconnecticutgeorgiaillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichigannevadanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiopennsylvaniarhode-islandtennesseevermontvirginiawest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.