BirdAnalyst
Species · BCR 23 · BBS 2025 Release · 1966–2024

Bell's Vireo In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionForest birds

Bell's Vireo in Prairie Hardwood Transition has fallen sharply: down 63% on the route-weighted index since 1971.

-63%Since 1971TrendPercent 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 →
26Routes 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 →
38YearsYears 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 Prairie Hardwood Transition. See the full index history below.

Bell's Vireo In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Bell's Vireo in Prairie Hardwood Transition is projected to stay roughly flat through 2028, near 0.01 (95% range 0.00–0.03). A 5-year backtest shows a typical error of ±44.5%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00–0.0395% 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 →
±44.5%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 Prairie Hardwood Transition is projected to stay roughly flat through 2028, near 0.01 (95% range 0.00–0.03). A 5-year backtest shows a typical error of ±44.5%, with 100% of held-out values landing inside the 95% band.19662028
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 →
20240.010.000.03
20250.010.000.03
20260.010.000.03
20270.010.000.03
20280.010.000.03

Routes In Prairie Hardwood Transition

Routes recording Bell's Vireo in Prairie Hardwood Transition.
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 →
New LondonMINNESOTA52000
TrempealeauWISCONSIN22011
AnnatonWISCONSIN22023
GuilfordILLINOIS12001
Cherry ValILLINOIS11972
Lake GalenaILLINOIS12013
KewannaINDIANA11993
New TroyMICHIGAN11990
Money CreekMINNESOTA11976
ChatfieldMINNESOTA11967
MillvilleMINNESOTA11979
Chatfield 2MINNESOTA12019
GilmantonWISCONSIN12007
MatherWISCONSIN11974
ClintonvilleWISCONSIN11996
Newburg CrnsWISCONSIN12015
ViroquaWISCONSIN11982
Rolling GrndWISCONSIN11990
PardeevilleWISCONSIN11994
Fall RiverWISCONSIN12017
N AndoverWISCONSIN12018
WiotaWISCONSIN11997
HebronWISCONSIN12013
VeronaWISCONSIN12015
HighlandWISCONSIN11999

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