BirdAnalyst
Species · BCR 16 · BBS 2026 Release · 1966–2025

Blue Jay In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauForest birds

Blue Jay in Southern Rockies / Colorado Plateau has fallen sharply: down 52% on the route-weighted index since 1986.

-52%Since 1986TrendPercent 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 →
8Routes 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 →
37YearsYears 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 declinecomputed 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 →

Blue Jay has fallen sharply in Southern Rockies / Colorado Plateau: down 52% on the route-weighted index since 1986.

Blue Jay In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Blue Jay in Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2030, near 0.03 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±53.5%, with 80% of held-out values landing inside the 95% band.

n/aChange 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 →
0.03Projected 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 →
0.00–0.0795% 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 →
±53.5%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, Blue Jay in Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2030, near 0.03 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±53.5%, with 80% of held-out values landing inside the 95% band.19822030
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 →
20260.030.000.07
20270.030.000.07
20280.030.000.07
20290.030.000.07
20300.030.000.07

Routes In Southern Rockies / Colorado Plateau

Routes recording Blue Jay 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 →
HarmonyCOLORADO62025
SummitvilleCOLORADO21999
GardnerCOLORADO21999
Cheesman LkCOLORADO12019
MoscaCOLORADO12002
Gribbles PrkCOLORADO12006
Gold HillCOLORADO12001
Gold Hill 2COLORADO12023

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