BirdAnalyst
Species · Louisiana · BBS 2025 Release · 1966–2024

Bronzed Cowbird Population Trend in Louisiana

All statesGeneralists

Bronzed Cowbird in Louisiana has declined: down 35% on the route-weighted index since 1990.

-35%Since 1990TrendPercent 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 →
11Routes 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 →
24YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bronzed Cowbird Trends in LouisianaNotable 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 Bronzed Cowbird in Louisiana. See the full index history below.

Bronzed Cowbird Population Forecast in Louisiana

If the recent trend holds, Bronzed Cowbird in Louisiana is projected to stay roughly flat through 2029, near 0.06 (95% range 0.00–0.18). A 5-year backtest shows a typical error of ±115.7%, 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 →
0.06Projected 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 →
0.00–0.1895% 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 →
±115.7%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 →
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 →
20250.060.000.18
20260.060.000.18
20270.060.000.18
20280.060.000.18
20290.060.000.18

Bronzed Cowbird Survey Routes in Louisiana

Routes recording Bronzed Cowbird in Louisiana.
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 →
Glencoe820112011
Gibson420012000
Carlisle319881988
Berwick220022002
Ramah120232000
Lafitte119901988
Belair120122012
Grand Isle120182010
Kraemer120242001
Baton Rouge120132013
Brousville120232018

Bronzed Cowbird Population Trend in Other States

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