BirdAnalyst
Species · BCR 31 · BBS 2025 Release · 1966–2024

Brown-headed Cowbird In Peninsular Florida

All regionsPeninsular FloridaGeneralists

Brown-headed Cowbird in Peninsular Florida has surged: up 525% on the route-weighted index since 1980.

+525%Since 1980TrendPercent 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 →
59Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
44YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 Peninsular Florida: up 525% on the route-weighted index since 1980.

Brown-headed Cowbird In Peninsular Florida Population Forecast

If the recent trend holds, Brown-headed Cowbird in Peninsular Florida is projected to stay roughly flat through 2029, near 0.75 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±194.7%, with 100% of held-out values landing inside the 95% band.

+5%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 →
0.75Projected 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 →
0.00–1.595% 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 →
±194.7%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 Peninsular Florida is projected to stay roughly flat through 2029, near 0.75 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±194.7%, with 100% of held-out values landing inside the 95% band.19742029
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 →
20250.730.001.5
20260.740.001.5
20270.740.001.5
20280.740.001.5
20290.750.001.5

Routes In Peninsular Florida

Routes recording Brown-headed Cowbird in Peninsular Florida.
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 →
Shawano 2FLORIDA212011
Citrus ParkFLORIDA122024
FlemingtonFLORIDA71999
Punta GordaFLORIDA52014
KissimmeeFLORIDA42003
MicanopyFLORIDA31991
RomeoFLORIDA32024
St AugustineFLORIDA32024
Sunniland GrFLORIDA32021
NobletonFLORIDA32024
ClewistonFLORIDA32023
Mt. OliveFLORIDA32024
Myakka HeadFLORIDA22010
Polk CityFLORIDA22021
ChildsFLORIDA22006
ScottsmoorFLORIDA22024
Pleasant GrFLORIDA22009
KendallFLORIDA21988
PalmdaleFLORIDA22014
Island GroveFLORIDA22018
CrewsvilleFLORIDA22011
Sugarloaf Key 2FLORIDA22015
Merritt IslFLORIDA22003
ChassahowitzFLORIDA22011
Dale MabryFLORIDA11985

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