BirdAnalyst
Species · BCR 19 · BBS 2025 Release · 1966–2024

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 201% on the route-weighted index since 1969.

+201%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 →
107Routes 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 →
57YearsYears 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 201% on the route-weighted index since 1969.

Forecast

If the recent trend holds, Bell's Vireo in Central Mixed Grass Prairie is projected to stay roughly flat through 2029, near 2.6 (95% range 1.5–3.7). A 5-year backtest shows a typical error of ±32.4%, with 40% of held-out values landing inside the 95% band.

-3%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 →
2.6Projected 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 →
1.5–3.795% 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 →
±32.4%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 Central Mixed Grass Prairie is projected to stay roughly flat through 2029, near 2.6 (95% range 1.5–3.7). A 5-year backtest shows a typical error of ±32.4%, with 40% 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 →
20252.41.33.5
20262.51.43.6
20272.51.43.6
20282.51.53.6
20292.61.53.7

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 ValleyTEXAS322024
MertzonTEXAS202019
KanopolisKANSAS182024
Mertzon 2TEXAS182024
WinchellTEXAS142024
SilverTEXAS132024
Shields 2TEXAS132023
BradyNEBRASKA112024
AlmeriaNEBRASKA82021
WallTEXAS62022
St JohnKANSAS52019
MinneapolisKANSAS52019
SolomonKANSAS52019
JamestownKANSAS52024
BelvidereNEBRASKA52024
BartleyNEBRASKA52024
BerwynNEBRASKA52009
HendleyNEBRASKA52024
GrimesOKLAHOMA52024
HanoverKANSAS42023
NenzelNEBRASKA42024
BoelusNEBRASKA42022
PhrosoOKLAHOMA42024
HaskellTEXAS42024

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