BirdAnalyst
Species · Minnesota · BBS 2026 Release · 1966–2025

Brown-headed Cowbird Population Trend in Minnesota

All statesGeneralists

Brown-headed Cowbird in Minnesota has surged: up 83% on the route-weighted index since 1969.

+83%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 →
90Routes 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 Brown-headed Cowbird 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 →

Brown-headed Cowbird has surged in Minnesota: up 83% on the route-weighted index since 1969.

Brown-headed Cowbird Population Forecast in Minnesota

If the recent trend holds, Brown-headed Cowbird in Minnesota is projected to fall about 26% by 2030 — from 22 in 2025 to a central estimate of 17 (95% range 10–23). A 5-year backtest shows a typical error of ±29.5%, with 40% of held-out values landing inside the 95% band.

-26%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 →
17Projected 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 →
10–2395% 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 →
±29.5%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, Brown-headed Cowbird in Minnesota is projected to fall about 26% by 2030 — from 22 in 2025 to a central estimate of 17 (95% range 10–23). A 5-year backtest shows a typical error of ±29.5%, with 40% 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 →
2026161023
2027161023
2028161023
2029171023
2030171023

Brown-headed Cowbird Survey Routes in Minnesota

Routes recording Brown-headed Cowbird 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 →
Fairmont6920251993
Chokio6720251969
Chokio North6520251993
Chandler5920251969
Tracy5620252004
Lockhart5620251993
Redwood Fall5320251978
Huntley5020251967
Frontenac5020241993
Sherburne Nr5020251990
Franklin4920251993
Millville4820251968
Appleton4420251978
New London4420241994
Tenney4320161978
Bagley4220061995
Arlington4120251967
Whitewater4120001994
Beltrami3720251967
Minnetonka3420251969
Wylie3420241969
Chatfield 23320252003
Osseo3220251967
Tyler3220251994
Ash Creek3120251975

Brown-headed Cowbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganmississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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