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

Bell's Vireo In Mississippi Alluvial Valley

All regionsMississippi Alluvial ValleyForest birds

Bell's Vireo in Mississippi Alluvial Valley has fallen sharply: down 60% on the route-weighted index since 1972.

-60%Since 1972TrendPercent 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 →
12Routes 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 →
25YearsYears 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 →

Bell's Vireo has fallen sharply in Mississippi Alluvial Valley: down 60% on the route-weighted index since 1972.

Bell's Vireo In Mississippi Alluvial Valley Population Forecast

If the recent trend holds, Bell's Vireo in Mississippi Alluvial Valley is projected to fall about 83% by 2028 — from 0.06 in 2023 to a central estimate of 0.01 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±69.4%, with 100% of held-out values landing inside the 95% band.

-83%Change by 2028TrendPercent 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 →
0.01Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1195% 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 →
±69.4%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, Bell's Vireo in Mississippi Alluvial Valley is projected to fall about 83% by 2028 — from 0.06 in 2023 to a central estimate of 0.01 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±69.4%, with 100% of held-out values landing inside the 95% band.19672028
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 →
20240.020.000.11
20250.020.000.11
20260.010.000.11
20270.010.000.11
20280.010.000.11

Routes In Mississippi Alluvial Valley

Routes recording Bell's Vireo 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 →
BlodgettMISSOURI22023
EudoraARKANSAS11975
HughesARKANSAS11975
West TylerARKANSAS11980
HarrisburgARKANSAS11997
AugustaARKANSAS11980
SaffellARKANSAS12014
MaynardARKANSAS12011
UlmARKANSAS11986
Augusta 2ARKANSAS12010
Crowley'S RidgeARKANSAS12016
Cp GirardeauMISSOURI12016

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