BirdAnalyst
Species · Rhode Island · BBS 2026 Release · 1966–2025

Brown-headed Cowbird Population Trend in Rhode Island

All statesGeneralists

Brown-headed Cowbird in Rhode Island has surged: up 154% on the route-weighted index since 1968.

+154%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 →
7Routes 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 →
54YearsYears 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 Rhode IslandNotable 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 Rhode Island: up 154% on the route-weighted index since 1968.

Brown-headed Cowbird Population Forecast in Rhode Island

If the recent trend holds, Brown-headed Cowbird in Rhode Island is projected to rise about 63% by 2030 — from 9.0 in 2025 to a central estimate of 15 (95% range 3.2–26). A 5-year backtest shows a typical error of ±45.9%, with 100% of held-out values landing inside the 95% band.

+63%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 →
15Projected 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 →
3.2–2695% 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 →
±45.9%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 Rhode Island is projected to rise about 63% by 2030 — from 9.0 in 2025 to a central estimate of 15 (95% range 3.2–26). A 5-year backtest shows a typical error of ±45.9%, with 100% 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 →
2026142.425
2027142.626
2028142.826
2029143.026
2030153.226

Brown-headed Cowbird Survey Routes in Rhode Island

Routes recording Brown-headed Cowbird in Rhode Island.
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 →
Quonset Pt1720251966
Block Island1020251987
Sachuest Pt819901966
Casimir Pulaski Sf720182016
Shannock520251973
Pulaski519921991
Wallum Lake420251973

Brown-headed Cowbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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