BirdAnalyst
Species · New York · BBS 2025 Release · 1966–2024

Brown-headed Cowbird Population Trend in New York

All statesGeneralists

Brown-headed Cowbird in New York has declined: down 42% on the route-weighted index since 1968.

-42%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 →
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 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 43% by 2029 — from 7.2 in 2024 to a central estimate of 4.1 (95% range 1.9–6.3). A 5-year backtest shows a typical error of ±38.4%, with 0% of held-out values landing inside the 95% band.

-43%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 →
4.1Projected 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 →
1.9–6.395% 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 →
±38.4%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 43% by 2029 — from 7.2 in 2024 to a central estimate of 4.1 (95% range 1.9–6.3). A 5-year backtest shows a typical error of ±38.4%, with 0% 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 →
20254.62.46.7
20264.42.36.6
20274.32.26.5
20284.22.16.4
20294.11.96.3

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
Churchville4420241968
Durham4319761966
Cicero Ctr3820241966
Cayuga3320241969
Ballston Lk2519951967
West Bangor2019981990
Penfield1920241968
Macdougall1720241969
Nashville1620181967
Dryden1520241966
West Seneca1520041966
Romulus1220001968
Castile1220241967
S Berne 21220242014
N Victory1219721967
Hauppauge1120081966
Somers1119771970
Catskills1120151967
Oxford1119761967
Hamburg1120241967
E Youngstown1120231966
Naples1120241966
Duanesburg1020241966
Orleans1020241967

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 2026-05-22.