BirdAnalyst
Species · BCR 34 · BBS 2026 Release · 1966–2025

Blue Grosbeak In Sierra Madre Occidental

All regionsSierra Madre OccidentalForest birds

Blue Grosbeak in Sierra Madre Occidental has edged up: up 22% on the route-weighted index since 1970.

+22%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 →
29Routes 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 →

No notable trend signals for Blue Grosbeak in Sierra Madre Occidental. See the full index history below.

Blue Grosbeak In Sierra Madre Occidental Population Forecast

If the recent trend holds, Blue Grosbeak in Sierra Madre Occidental is projected to fall about 19% by 2030 — from 3.6 in 2025 to a central estimate of 2.9 (95% range 0.00–7.7). A 5-year backtest shows a typical error of ±35.5%, with 100% of held-out values landing inside the 95% band.

-19%Change 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 →
2.9Projected 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 →
0.00–7.795% 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 →
±35.5%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 Grosbeak in Sierra Madre Occidental is projected to fall about 19% by 2030 — from 3.6 in 2025 to a central estimate of 2.9 (95% range 0.00–7.7). A 5-year backtest shows a typical error of ±35.5%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20263.20.008.0
20273.10.008.0
20283.10.007.9
20293.00.007.8
20302.90.007.7

Routes In Sierra Madre Occidental

Routes recording Blue Grosbeak in Sierra Madre Occidental.
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 →
PomereneARIZONA422025
Sunizona 2ARIZONA172025
McnealARIZONA122025
PortalARIZONA82025
PatagoniaARIZONA52025
SunizonaARIZONA51997
AmadoARIZONA52025
Peña BlancaARIZONA42024
RuckerARIZONA42009
Skull ValleyARIZONA32024
SahuaritaARIZONA32024
Carr MtnARIZONA32022
Skull Valley 2ARIZONA22025
DragoonARIZONA22009
Vicks PeakNEW-MEXICO22025
PrescottARIZONA12025
Mormon LakeARIZONA11974
Aztec PeakARIZONA11975
BlueARIZONA11989
San SimonARIZONA12024
Forest LakesARIZONA12005
Bartlett ResARIZONA12011
CutterARIZONA11998
RedingtonARIZONA12025
Clay SpringARIZONA12022

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