BirdAnalyst
Species · BCR 27 · BBS 2026 Release · 1966–2025

Blue Grosbeak In Southeastern Coastal Plain

All regionsSoutheastern Coastal PlainForest birds

Blue Grosbeak in Southeastern Coastal Plain has surged: up 108% on the route-weighted index since 1968.

+108%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 →
344Routes 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 →

long arc increasecomputed 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 Grosbeak has surged in Southeastern Coastal Plain: up 108% on the route-weighted index since 1968.

Blue Grosbeak In Southeastern Coastal Plain Population Forecast

If the recent trend holds, Blue Grosbeak in Southeastern Coastal Plain is projected to stay roughly flat through 2030, near 12 (95% range 9.8–14). A 5-year backtest shows a typical error of ±16%, with 60% of held-out values landing inside the 95% band.

+9%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 →
12Projected 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 →
9.8–1495% 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 →
±16%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 Southeastern Coastal Plain is projected to stay roughly flat through 2030, near 12 (95% range 9.8–14). A 5-year backtest shows a typical error of ±16%, with 60% 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 →
2026119.414
2027129.514
2028129.614
2029129.714
2030129.814

Routes In Southeastern Coastal Plain

Routes recording Blue Grosbeak in Southeastern Coastal Plain.
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 →
LovedaleFLORIDA612011
Rock ChapelALABAMA462024
SpeedNORTH-CAROLINA392025
JacksonNORTH-CAROLINA342017
MansfieldTENNESSEE322025
HumboldtTENNESSEE322025
NewvilleVIRGINIA312024
BrownsvilleTENNESSEE302025
HarrellALABAMA282025
FitzgeraldGEORGIA272025
Big SandyTENNESSEE272025
KinstonNORTH-CAROLINA262024
RhemsNORTH-CAROLINA261993
GenoaNORTH-CAROLINA262025
GrangeburgALABAMA252024
Miller XrdsFLORIDA252019
OwensboroGEORGIA252025
New HopeFLORIDA242011
Eglin A.F.B.FLORIDA242011
Cypress LakesNORTH-CAROLINA242025
New HollandSOUTH-CAROLINA242025
NewsomsVIRGINIA242024
ElamvilleALABAMA232025
WorkmoreGEORGIA232025
Minter TweedGEORGIA232025

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