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Species · BCR 19 · BBS 2026 Release · 1966–2025

Bell's Vireo In Central Mixed Grass Prairie

All regionsCentral Mixed Grass PrairieForest birds

Bell's Vireo in Central Mixed Grass Prairie has surged: up 183% on the route-weighted index since 1969.

+183%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 →
109Routes 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 →
58YearsYears 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 increasecomputed 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 surged in Central Mixed Grass Prairie: up 183% on the route-weighted index since 1969.

Bell's Vireo In Central Mixed Grass Prairie Population Forecast

If the recent trend holds, Bell's Vireo in Central Mixed Grass Prairie is projected to stay roughly flat through 2030, near 2.6 (95% range 1.6–3.7). A 5-year backtest shows a typical error of ±27.1%, with 80% of held-out values landing inside the 95% band.

-1%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 →
2.6Projected 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 →
1.6–3.795% 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 →
±27.1%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 Central Mixed Grass Prairie is projected to stay roughly flat through 2030, near 2.6 (95% range 1.6–3.7). A 5-year backtest shows a typical error of ±27.1%, 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 →
20262.51.43.6
20272.51.43.6
20282.61.53.6
20292.61.53.7
20302.61.63.7

Routes In Central Mixed Grass Prairie

Routes recording Bell's Vireo in Central Mixed Grass Prairie.
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 →
EldoradoTEXAS412023
Pear ValleyTEXAS352025
BradyNEBRASKA202025
MertzonTEXAS202019
WinchellTEXAS152025
Mertzon 2TEXAS142025
SilverTEXAS142025
KanopolisKANSAS132025
AlmeriaNEBRASKA82021
HendleyNEBRASKA82025
Shields 2TEXAS82025
Liberty 3NEBRASKA72025
WallTEXAS62022
St JohnKANSAS52019
MinneapolisKANSAS52019
JamestownKANSAS52024
BerwynNEBRASKA52009
PhrosoOKLAHOMA52025
HanoverKANSAS42025
BartleyNEBRASKA42025
BoelusNEBRASKA42022
GrimesOKLAHOMA42025
GirardTEXAS42025
AlbertKANSAS32024
HollenbergKANSAS32025

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