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Species · Minnesota · BBS 2026 Release · 1966–2025

Mourning Warbler Population Trend in Minnesota

All statesForest birds

Mourning Warbler in Minnesota has edged up: up 23% on the route-weighted index since 1969.

+23%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 →
45Routes 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 Mourning 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 Mourning Warbler in Minnesota. See the full index history below.

Mourning Warbler Population Forecast in Minnesota

If the recent trend holds, Mourning Warbler in Minnesota is projected to fall about 34% by 2030 — from 4.5 in 2025 to a central estimate of 3.0 (95% range 0.86–5.2). A 5-year backtest shows a typical error of ±43.9%, with 20% of held-out values landing inside the 95% band.

-34%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 →
3.0Projected 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 →
0.86–5.295% 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 →
±43.9%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, Mourning Warbler in Minnesota is projected to fall about 34% by 2030 — from 4.5 in 2025 to a central estimate of 3.0 (95% range 0.86–5.2). A 5-year backtest shows a typical error of ±43.9%, with 20% 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 →
20263.11.005.3
20273.10.965.3
20283.10.935.2
20293.00.895.2
20303.00.865.2

Mourning Warbler Survey Routes in Minnesota

Routes recording Mourning 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 →
Hart Lake4720251967
Lockport3620251967
Jordan2320251993
Sherry Lake2020221969
Glendale2020251993
Sawbill Lndg1920251973
Hovland1820251973
Chisholm1720242019
Floodwood1620251967
Crane Lake1620251970
Cromwell1520251967
Bigfork1220251993
Babbitt1020251994
Little Fork920241970
Nett Lake720242013
Sawbill Camp620251993
Island Lake520171967
Cohasset520221973
Bena519771977
Cass Lake420161981
Red Lake420251993
Mcgregor320251994
Blackduck320222004
Nebish220251982
Backus220141967

Mourning Warbler Population Trend in Other States

connecticutillinoisindianamainemarylandmassachusettsmichigannew-hampshirenew-yorknorth-dakotaohiopennsylvaniavermontwest-virginiawisconsin

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