BirdAnalyst
Species · BCR 29 · BBS 2026 Release · 1966–2025

Blue Grosbeak In Piedmont

All regionsPiedmontForest birds

Blue Grosbeak in Piedmont has edged up: up 22% on the route-weighted index since 1968.

+22%Since 1968TrendPercent 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 →
154Routes 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 →
59YearsYears 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 Piedmont. See the full index history below.

Blue Grosbeak In Piedmont Population Forecast

If the recent trend holds, Blue Grosbeak in Piedmont is projected to fall about 11% by 2030 — from 6.5 in 2025 to a central estimate of 5.7 (95% range 3.9–7.6). A 5-year backtest shows a typical error of ±9.4%, with 100% of held-out values landing inside the 95% band.

-11%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 →
5.7Projected 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 →
3.9–7.695% 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 →
±9.4%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, Blue Grosbeak in Piedmont is projected to fall about 11% by 2030 — from 6.5 in 2025 to a central estimate of 5.7 (95% range 3.9–7.6). A 5-year backtest shows a typical error of ±9.4%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20265.73.97.5
20275.73.97.6
20285.73.97.6
20295.73.97.6
20305.73.97.6

Routes In Piedmont

Routes recording Blue Grosbeak in Piedmont.
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 →
FinchleyVIRGINIA282021
Little MtnSOUTH-CAROLINA251988
MaxeysGEORGIA232024
BrodnaxVIRGINIA232025
RutledgeGEORGIA212025
RinggoldVIRGINIA202025
LincolntonGEORGIA182017
AthensGEORGIA182025
Rock BranchGEORGIA182025
Lincolnton 2GEORGIA162025
Church RoadVIRGINIA162025
YoungsvilleNORTH-CAROLINA152025
BullockNORTH-CAROLINA152025
GladysVIRGINIA152025
MillervilleALABAMA142025
Liberty CityALABAMA142011
PendletonSOUTH-CAROLINA141976
GreenwoodSOUTH-CAROLINA142025
Sharon 2GEORGIA132025
JordanNORTH-CAROLINA132025
ClimaxNORTH-CAROLINA132025
SheffieldNORTH-CAROLINA132025
DurhamNORTH-CAROLINA132025
SiloamNORTH-CAROLINA132025
ConcordVIRGINIA132024

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