BirdAnalyst
Species · BCR 26 · BBS 2025 Release · 1966–2024

Bronzed Cowbird In Mississippi Alluvial Valley

All regionsMississippi Alluvial ValleyGeneralists

Bronzed Cowbird in Mississippi Alluvial Valley has fallen sharply: down 51% on the route-weighted index since 2001.

-51%Since 2001TrendPercent 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 →
8Routes 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 →
22YearsYears 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 declinecomputed 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 →

Bronzed Cowbird has fallen sharply in Mississippi Alluvial Valley: down 51% on the route-weighted index since 2001.

Bronzed Cowbird In Mississippi Alluvial Valley Population Forecast

If the recent trend holds, Bronzed Cowbird in Mississippi Alluvial Valley is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±39.7%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.02Projected 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 →
0.00–0.1095% 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 →
±39.7%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, Bronzed Cowbird in Mississippi Alluvial Valley is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±39.7%, with 100% of held-out values landing inside the 95% band.19882029
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 →
20250.030.000.11
20260.030.000.11
20270.030.000.10
20280.030.000.10
20290.020.000.10

Routes In Mississippi Alluvial Valley

Routes recording Bronzed Cowbird in Mississippi Alluvial Valley.
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 →
GibsonLOUISIANA42001
CarlisleLOUISIANA31988
BerwickLOUISIANA22002
RamahLOUISIANA12023
BrousvilleLOUISIANA12023
BelairLOUISIANA12012
KraemerLOUISIANA12024
Baton RougeLOUISIANA12013

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