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

Common Grackle In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauGeneralists

Common Grackle in Southern Rockies / Colorado Plateau has fallen sharply: down 65% on the route-weighted index since 1971.

-65%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 →
80Routes 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 →
55YearsYears 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 →

Common Grackle has fallen sharply in Southern Rockies / Colorado Plateau: down 65% on the route-weighted index since 1971.

Common Grackle In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Common Grackle in Southern Rockies / Colorado Plateau is projected to rise about 11% by 2029 — from 0.30 in 2024 to a central estimate of 0.33 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±243.8%, with 100% of held-out values landing inside the 95% band.

+11%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 →
0.33Projected 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 →
0.00–1.795% 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 →
±243.8%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, Common Grackle in Southern Rockies / Colorado Plateau is projected to rise about 11% by 2029 — from 0.30 in 2024 to a central estimate of 0.33 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±243.8%, 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 →
20250.420.001.8
20260.400.001.8
20270.380.001.8
20280.360.001.7
20290.330.001.7

Routes In Southern Rockies / Colorado Plateau

Routes recording Common Grackle 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 →
HarmonyCOLORADO232024
ParlinCOLORADO162018
Fletcher PkWYOMING102024
PowderhornCOLORADO92001
BrookhurstWYOMING92019
Colona 2COLORADO82021
SummitvilleCOLORADO81994
CapulinNEW-MEXICO81993
Baxter PassCOLORADO72013
Wilson CreekCOLORADO62018
Weston PassCOLORADO62000
AnimasCOLORADO62000
ValenciaNEW-MEXICO61997
TarryallCOLORADO52022
Angel FireNEW-MEXICO52002
MoabUTAH51998
HannaUTAH52001
FruitaCOLORADO42007
Dunckley PasCOLORADO42024
Deadman Rd.COLORADO41994
MoscaCOLORADO41999
Gold HillCOLORADO42012
Sybille CynWYOMING42014
YampaCOLORADO32023
BufordCOLORADO32022

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