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Species · Minnesota · BBS 2025 Release · 1966–2024

Black-throated Green Warbler Population Trend in Minnesota

All statesForest birds

Black-throated Green Warbler in Minnesota has surged: up 353% on the route-weighted index since 1969.

+353%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 →
34Routes 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 Black-throated Green 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 →

Black-throated Green Warbler has surged in Minnesota: up 353% on the route-weighted index since 1969.

Black-throated Green Warbler Population Forecast in Minnesota

If the recent trend holds, Black-throated Green Warbler in Minnesota is projected to stay roughly flat through 2029, near 2.0 (95% range 1.3–2.7). A 5-year backtest shows a typical error of ±19.7%, with 80% of held-out values landing inside the 95% band.

+5%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 →
2.0Projected 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 →
1.3–2.795% 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 →
±19.7%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, Black-throated Green Warbler in Minnesota is projected to stay roughly flat through 2029, near 2.0 (95% range 1.3–2.7). A 5-year backtest shows a typical error of ±19.7%, with 80% 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 →
20251.91.22.5
20261.91.22.6
20271.91.22.6
20281.91.22.6
20292.01.32.7

Black-throated Green Warbler Survey Routes in Minnesota

Routes recording Black-throated Green 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 →
Hovland3120241973
Blackduck3020222004
Lockport2320241967
Bigfork1120241993
Chisholm1120242019
Sawbill Camp1020241993
Jordan1020231993
Sherry Lake720221974
Cromwell520241967
Island Lake420171975
Bena419771967
Cass Lake320161980
Floodwood320221970
Cohasset320221974
Red Lake320241993
Sawbill Lndg220241973
Bemidji219681967
Debs220241970
Little Fork219701970
Lude220171992
Glendale220241993
Tamarac Nwr120161991
Nebish120232011
Princeton119931993
Backus120212015

Black-throated Green Warbler Population Trend in Other States

alabamaarkansasconnecticutgeorgiaindianakentuckymainemarylandmassachusettsmichiganmissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseevermontvirginiawest-virginiawisconsin

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