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Species · Louisiana · BBS 2025 Release · 1966–2024

Bachman's Sparrow Population Trend in Louisiana

All statesGeneralists

Bachman's Sparrow in Louisiana has collapsed: down 95% on the route-weighted index since 1969.

-95%Since 1969TrendPercent 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 →
30Routes 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 →
50YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bachman's Sparrow 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 →

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 →

Bachman's Sparrow has collapsed in Louisiana: down 95% on the route-weighted index since 1969.

Bachman's Sparrow Population Forecast in Louisiana

If the recent trend holds, Bachman's Sparrow in Louisiana is projected to fall about 100% by 2029 — from 0.10 in 2024 to a central estimate of 0.00 (95% range 0.00–0.68). A 5-year backtest shows a typical error of ±1089.4%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.6895% 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 →
±1089.4%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, Bachman's Sparrow in Louisiana is projected to fall about 100% by 2029 — from 0.10 in 2024 to a central estimate of 0.00 (95% range 0.00–0.68). A 5-year backtest shows a typical error of ±1089.4%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.000.000.68
20260.000.000.68
20270.000.000.68
20280.000.000.68
20290.000.000.68

Bachman's Sparrow Survey Routes in Louisiana

Routes recording Bachman's Sparrow 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 →
Mer Rouge1120061969
Pearl River720081989
Lacombe619831967
De Quincy419981998
Natchez420241992
Derry319891970
Fort Polk319751967
Slidell319881984
Derry 2319971990
Fishville220081967
Hargis 2220132013
Clay219721968
Greensburg219921988
Roseland119901967
Bickham119861986
Fort Jessup120182018
Ivan119981998
Easton119811975
De Ridder120141968
Cypress119731971
Chatham119731968
Longstreet119841968
Fillmore119691969
Trout119971997
Marion119951995

Bachman's Sparrow Population Trend in Other States

alabamaarkansasfloridageorgiakentuckymississippimissourinorth-carolinaohiooklahomasouth-carolinatennesseetexasvirginia

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