BirdAnalyst
Species · New York · BBS 2026 Release · 1966–2025

Brown-headed Cowbird Population Trend in New York

All statesGeneralists

Brown-headed Cowbird in New York has declined: down 40% on the route-weighted index since 1968.

-40%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 →
128Routes 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 →
59YearsYears 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 New YorkNotable 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 Brown-headed Cowbird in New York. See the full index history below.

Brown-headed Cowbird Population Forecast in New York

If the recent trend holds, Brown-headed Cowbird in New York is projected to fall about 44% by 2030 — from 7.5 in 2025 to a central estimate of 4.2 (95% range 1.9–6.5). A 5-year backtest shows a typical error of ±40.5%, with 0% of held-out values landing inside the 95% band.

-44%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 →
4.2Projected 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 →
1.9–6.595% 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 →
±40.5%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 New York is projected to fall about 44% by 2030 — from 7.5 in 2025 to a central estimate of 4.2 (95% range 1.9–6.5). A 5-year backtest shows a typical error of ±40.5%, with 0% of held-out values landing inside the 95% band.19662030
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 →
20264.72.46.9
20274.52.36.8
20284.42.26.7
20294.32.16.6
20304.21.96.5

Brown-headed Cowbird Survey Routes in New York

Routes recording Brown-headed Cowbird in New York.
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 →
Jones Beach4420131966
Durham4319761966
Cayuga4320251969
Ballston Lk2519951967
Macdougall2420251969
Churchville2320251968
Orleans2220251967
West Bangor2019981990
E Youngstown1820251966
Mt Morris1720251967
Harris Hill1720252005
Nashville1620181967
Naples1620251966
West Seneca1520041966
Penfield1520251968
Cicero Ctr1320251966
Romulus1220001968
Hamburg1220251967
N Victory1219721967
Hauppauge1120081966
Somers1119771970
Catskills1120151967
Oxford1119761967
Salem1120251967
Branchport1020241967

Brown-headed Cowbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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