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Species · Mississippi · BBS 2025 Release · 1966–2024

Brown-headed Cowbird Population Trend in Mississippi

All statesGeneralists

Brown-headed Cowbird in Mississippi has risen sharply: up 56% on the route-weighted index since 1968.

+56%Since 1968TrendPercent 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 →
74Routes 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 MississippiNotable 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 Mississippi: up 56% on the route-weighted index since 1968.

Brown-headed Cowbird Population Forecast in Mississippi

If the recent trend holds, Brown-headed Cowbird in Mississippi is projected to fall about 26% by 2029 — from 17 in 2024 to a central estimate of 12 (95% range 7.0–18). A 5-year backtest shows a typical error of ±13.8%, with 100% of held-out values landing inside the 95% band.

-26%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 →
12Projected 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 →
7.0–1895% 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 →
±13.8%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 Mississippi is projected to fall about 26% by 2029 — from 17 in 2024 to a central estimate of 12 (95% range 7.0–18). A 5-year backtest shows a typical error of ±13.8%, with 100% of held-out values landing inside the 95% band.19662029
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 →
2025126.818
2026126.918
2027126.918
2028127.018
2029127.018

Brown-headed Cowbird Survey Routes in Mississippi

Routes recording Brown-headed Cowbird in Mississippi.
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 →
Dundee5420221970
Tallahatchie5220241996
Winterville4120112009
Duck Hill3520241968
Trace Madison3120192015
Cockrum3020241966
Trace Lorman3020192016
Vicksburg Np2520212016
Holly Springs2420242009
Tupelo2320221966
Lake2220241966
Dahomey Nwr2020242011
Delta N.F.2020211995
Tchula 31920241995
Olive Branch 21920222016
Aberdeen1720241970
Trace South1620192008
Tchula1519751970
Panther Swamp Nwr1520182016
Olive Branch1420011969
Walthall1319871970
Amite River1320132008
Tchula 21319941976
Beverly1220111966
Corinth1220241972

Brown-headed Cowbird Population Trend in Other States

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

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