BirdAnalyst
Species · BCR 24 · BBS 2026 Release · 1966–2025

Blue Grosbeak In Central Hardwoods

All regionsCentral HardwoodsForest birds

Blue Grosbeak in Central Hardwoods has surged: up 264% on the route-weighted index since 1968.

+264%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 →
161Routes 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 Central Hardwoods: up 264% on the route-weighted index since 1968.

Blue Grosbeak In Central Hardwoods Population Forecast

If the recent trend holds, Blue Grosbeak in Central Hardwoods is projected to rise about 16% by 2030 — from 6.1 in 2025 to a central estimate of 7.1 (95% range 6.0–8.1). A 5-year backtest shows a typical error of ±7.3%, with 100% of held-out values landing inside the 95% band.

+16%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 →
7.1Projected 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 →
6.0–8.195% 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 →
±7.3%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 Central Hardwoods is projected to rise about 16% by 2030 — from 6.1 in 2025 to a central estimate of 7.1 (95% range 6.0–8.1). A 5-year backtest shows a typical error of ±7.3%, 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 →
20266.85.77.8
20276.95.87.9
20286.95.98.0
20297.06.08.1
20307.16.08.1

Routes In Central Hardwoods

Routes recording Blue Grosbeak in Central Hardwoods.
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 →
Bays ForkKENTUCKY242019
GlenTENNESSEE232025
NewberryINDIANA212025
KeysburgKENTUCKY192025
Ravenden SpringsARKANSAS182015
BremenILLINOIS182025
Wheeler DamALABAMA172025
CelestineINDIANA172025
HegiraKENTUCKY172024
FarwellARKANSAS162018
ComptonARKANSAS152022
Beaverdam LkILLINOIS152023
BrownvilleILLINOIS152025
CollinwoodTENNESSEE152025
Iron BridgeKENTUCKY141998
Sulphur LickKENTUCKY142024
DemunbrunsKENTUCKY142021
CentertownMISSOURI142025
JoyKENTUCKY132023
Hodgenville 2KENTUCKY132023
CourtlandALABAMA122023
Peace ValleyMISSOURI122025
CampbellsvilleTENNESSEE122017
SwaimALABAMA112025
PulaskiILLINOIS112025

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