BirdAnalyst
Species · BCR 27 · BBS 2025 Release · 1966–2024

Blue Grosbeak In Southeastern Coastal Plain

All regionsSoutheastern Coastal PlainGeneralists

Blue Grosbeak in Southeastern Coastal Plain has surged: up 100% on the route-weighted index since 1968.

+100%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 →
342Routes 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 →

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 100% 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 2029, near 12 (95% range 9.7–14). A 5-year backtest shows a typical error of ±21.1%, with 40% of held-out values landing inside the 95% band.

+9%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 →
12Projected 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 →
9.7–1495% 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 →
±21.1%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 2029, near 12 (95% range 9.7–14). A 5-year backtest shows a typical error of ±21.1%, with 40% 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 →
2025119.314
2026129.414
2027129.514
2028129.614
2029129.714

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-CAROLINA392024
JacksonNORTH-CAROLINA342017
NewvilleVIRGINIA312024
MansfieldTENNESSEE302024
CottontonALABAMA272024
BlountstownFLORIDA262024
KinstonNORTH-CAROLINA262024
RhemsNORTH-CAROLINA261993
GrangeburgALABAMA252024
Miller XrdsFLORIDA252019
WadleyGEORGIA252024
DudleyNORTH-CAROLINA252024
Cypress LakesNORTH-CAROLINA252024
New HopeFLORIDA242011
Eglin A.F.B.FLORIDA242011
WorkmoreGEORGIA242019
NewsomsVIRGINIA242024
BostonGEORGIA232024
White HillGEORGIA232024
LovelacevileKENTUCKY232024
ShallotteNORTH-CAROLINA231991
BeargrassNORTH-CAROLINA231981
Cypress CrNORTH-CAROLINA232022

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