BirdAnalyst
Species · BCR 16 · BBS 2025 Release · 1966–2024

Evening Grosbeak In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauGeneralists

Evening Grosbeak in Southern Rockies / Colorado Plateau has risen sharply: up 73% on the route-weighted index since 1970.

+73%Since 1970TrendPercent 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 →
81Routes 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 →
51YearsYears 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 →

Evening Grosbeak has risen sharply in Southern Rockies / Colorado Plateau: up 73% on the route-weighted index since 1970.

Evening Grosbeak In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Evening Grosbeak in Southern Rockies / Colorado Plateau is projected to rise about 91% by 2029 — from 0.24 in 2024 to a central estimate of 0.46 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±38.4%, with 100% of held-out values landing inside the 95% band.

+91%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 →
0.46Projected 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 →
0.00–1.495% 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 →
±38.4%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, Evening Grosbeak in Southern Rockies / Colorado Plateau is projected to rise about 91% by 2029 — from 0.24 in 2024 to a central estimate of 0.46 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±38.4%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.460.001.4
20260.460.001.4
20270.460.001.4
20280.460.001.4
20290.460.001.4

Routes In Southern Rockies / Colorado Plateau

Routes recording Evening Grosbeak in Southern Rockies / Colorado Plateau.
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 →
Angel FireNEW-MEXICO182002
Owl Creek PassCOLORADO112024
SummitvilleCOLORADO102015
FlattopsCOLORADO82017
Groundhog RsCOLORADO82019
PowderhornCOLORADO82023
BufordWYOMING82018
Rifle FallsCOLORADO72003
Main CanyonUTAH72002
Uintah NfUTAH61994
Wet Mtns.COLORADO51994
ParlinCOLORADO41988
TarryallCOLORADO42023
Dolores RivCOLORADO42021
Pinos CreekCOLORADO41989
CokedaleCOLORADO42023
Marshall PasCOLORADO42011
GardnerCOLORADO42008
GallinasNEW-MEXICO42021
AltonUTAH41998
BrookhurstWYOMING41999
TsaileARIZONA31996
ColonaCOLORADO32010
CastletonCOLORADO32024
GuffeyCOLORADO32024

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