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

Chestnut-sided Warbler Population Trend in Minnesota

All statesForest birds

Chestnut-sided Warbler in Minnesota has risen sharply: up 57% on the route-weighted index since 1969.

+57%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 →
57YearsYears 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 →

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 →

Chestnut-sided Warbler has risen sharply in Minnesota: up 56% on the route-weighted index since 1969.

Chestnut-sided Warbler Population Forecast in Minnesota

If the recent trend holds, Chestnut-sided Warbler in Minnesota is projected to fall about 12% by 2029 — from 8.7 in 2024 to a central estimate of 7.7 (95% range 4.0–11). A 5-year backtest shows a typical error of ±35.5%, with 60% of held-out values landing inside the 95% band.

-12%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 →
7.7Projected 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 →
4.0–1195% 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 →
±35.5%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 12% by 2029 — from 8.7 in 2024 to a central estimate of 7.7 (95% range 4.0–11). A 5-year backtest shows a typical error of ±35.5%, with 60% of held-out values landing inside the 95% band.19672029
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 →
20257.74.011
20267.74.011
20277.74.011
20287.74.011
20297.74.011

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 Lake5220241967
Lockport4320241967
Jordan4020231993
Crane Lake3720241969
Bigfork3720241993
Sawbill Lndg3620241973
Blackduck3220222004
Bena2519771967
Sawbill Camp2520241993
Cass Lake2420161980
Glendale2320241993
Babbitt2120231994
Tamarac Nwr2020241991
Hovland2020241973
Nett Lake2020242013
Lude1720231979
Mahtowa1620231993
Cromwell1520241967
Cohasset1520221973
Debs1520241969
Nebish1420231982
Mcgregor1320241993
Floodwood1220241967

Chestnut-sided Warbler Population Trend in Other States

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

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