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

Brown-headed Cowbird Population Trend in Minnesota

All statesGeneralists

Brown-headed Cowbird in Minnesota has risen sharply: up 71% on the route-weighted index since 1969.

+71%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 →
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 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 risen sharply in Minnesota: up 71% 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 28% by 2029 — from 22 in 2024 to a central estimate of 16 (95% range 9.7–22). A 5-year backtest shows a typical error of ±26.2%, with 60% of held-out values landing inside the 95% band.

-28%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 →
16Projected 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 →
9.7–2295% 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 →
±26.2%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 28% by 2029 — from 22 in 2024 to a central estimate of 16 (95% range 9.7–22). A 5-year backtest shows a typical error of ±26.2%, 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 →
2025169.722
2026169.722
2027169.722
2028169.722
2029169.722

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 →
Chokio North6520241993
Franklin6120241993
Fairmont5920231993
Chokio5720241969
Sherburne Nr5420241990
Lockhart5220241993
Chandler5120231969
Redwood Fall5020241978
Worthington5020242004
Frontenac5020241993
Tracy5020242004
Le Center4920231993
Ash Creek4720241975
Knapp4720241967
New London4420241994
Arlington4320241967
Tenney4320161978
Bagley4220061995
Whitewater4120001994
Appleton4020241978
Huntley3720241967
Wylie3420241969
Minnetonka3320241969
Beltrami3220241967
Brook Park3220241998

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 2026-05-22.