BirdAnalyst
Species · BCR 17 · BBS 2026 Release · 1966–2025

Bell's Vireo In Badlands and Prairies

All regionsBadlands and PrairiesForest birds

Bell's Vireo in Badlands and Prairies has declined: down 33% on the route-weighted index since 1969.

-33%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 →
18Routes 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 →
47YearsYears 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 →

No notable trend signals for Bell's Vireo in Badlands and Prairies. See the full index history below.

Bell's Vireo In Badlands and Prairies Population Forecast

If the recent trend holds, Bell's Vireo in Badlands and Prairies is projected to fall about 61% by 2030 — from 0.19 in 2025 to a central estimate of 0.07 (95% range 0.00–0.18). A 5-year backtest shows a typical error of ±51.8%, with 80% of held-out values landing inside the 95% band.

-61%Change by 2030TrendPercent 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 →
0.07Projected 2030 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 →
±51.8%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 Badlands and Prairies is projected to fall about 61% by 2030 — from 0.19 in 2025 to a central estimate of 0.07 (95% range 0.00–0.18). A 5-year backtest shows a typical error of ±51.8%, with 80% of held-out values landing inside the 95% band.19672030
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 →
20260.070.000.18
20270.070.000.18
20280.070.000.18
20290.070.000.18
20300.070.000.18

Routes In Badlands and Prairies

Routes recording Bell's Vireo in Badlands and Prairies.
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 →
RosebudSOUTH-DAKOTA72010
BadlandsSOUTH-DAKOTA52025
ChamberlainSOUTH-DAKOTA42011
CrookstonNEBRASKA32025
Oglala Nat. Grass.NEBRASKA32002
RockyfordSOUTH-DAKOTA32025
LacreekSOUTH-DAKOTA32025
WinnerSOUTH-DAKOTA22022
LaplantSOUTH-DAKOTA21971
PromiseSOUTH-DAKOTA22015
SolenNORTH-DAKOTA12025
Ft ThompsonSOUTH-DAKOTA12011
OwankaSOUTH-DAKOTA11985
OttumwaSOUTH-DAKOTA11973
Cedar PassSOUTH-DAKOTA11975
Fort PierreSOUTH-DAKOTA12021
MaurineSOUTH-DAKOTA12023
White RiverSOUTH-DAKOTA12013

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.