BirdAnalyst
Species · BCR 29 · BBS 2025 Release · 1966–2024

Blue Grosbeak In Piedmont

All regionsPiedmontGeneralists

Blue Grosbeak in Piedmont has edged up: up 15% on the route-weighted index since 1968.

+15%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 →
58YearsYears 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.

Forecast

If the recent trend holds, Blue Grosbeak in Piedmont is projected to stay roughly flat through 2029, near 5.7 (95% range 3.9–7.5). A 5-year backtest shows a typical error of ±6.9%, with 100% of held-out values landing inside the 95% band.

-5%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 →
5.7Projected 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 →
3.9–7.595% 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 →
±6.9%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 stay roughly flat through 2029, near 5.7 (95% range 3.9–7.5). A 5-year backtest shows a typical error of ±6.9%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20255.73.87.5
20265.73.87.5
20275.73.87.5
20285.73.87.5
20295.73.97.5

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
Rock BranchGEORGIA202024
LowrysSOUTH-CAROLINA202021
JoannaSOUTH-CAROLINA202023
LincolntonGEORGIA182017
RutledgeGEORGIA182024
OakboroNORTH-CAROLINA182024
BullockNORTH-CAROLINA182024
YoungsvilleNORTH-CAROLINA162024
BiscoeNORTH-CAROLINA162017
RinggoldVIRGINIA162024
GladysVIRGINIA162024
Lincolnton 2GEORGIA152024
DurhamNORTH-CAROLINA152024
Liberty CityALABAMA142011
MonticelloNORTH-CAROLINA142024
PendletonSOUTH-CAROLINA141976
HallVIRGINIA142023
Church RoadVIRGINIA142024
BrodnaxVIRGINIA142024
ConcordVIRGINIA132024
FlayNORTH-CAROLINA122024
ClimaxNORTH-CAROLINA112024

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