BirdAnalyst
Species · BCR 37 · BBS 2025 Release · 1966–2024

Blue Grosbeak In Gulf Coastal Prairie

All regionsGulf Coastal PrairieGeneralists

Blue Grosbeak in Gulf Coastal Prairie has surged: up 599% on the route-weighted index since 1975.

+599%Since 1975TrendPercent 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 →
33Routes 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 →
44YearsYears 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 Gulf Coastal Prairie: up 599% on the route-weighted index since 1975.

Forecast

If the recent trend holds, Blue Grosbeak in Gulf Coastal Prairie is projected to rise about 49% by 2029 — from 0.91 in 2024 to a central estimate of 1.3 (95% range 0.74–2.0). A 5-year backtest shows a typical error of ±34.7%, with 100% of held-out values landing inside the 95% band.

+49%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 →
1.3Projected 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 →
0.74–2.095% 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 →
±34.7%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 Gulf Coastal Prairie is projected to rise about 49% by 2029 — from 0.91 in 2024 to a central estimate of 1.3 (95% range 0.74–2.0). A 5-year backtest shows a typical error of ±34.7%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20251.30.641.9
20261.30.671.9
20271.30.691.9
20281.30.711.9
20291.30.742.0

Routes In Gulf Coastal Prairie

Routes recording Blue Grosbeak in Gulf Coastal Prairie.
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 →
San PedroTEXAS102023
Loyola Beach 2TEXAS102024
Loyola BeachTEXAS62009
Vinton 2LOUISIANA52024
VintonLOUISIANA42009
GlencoeLOUISIANA32008
L. Atascosa NwrTEXAS32023
Goliad PrairieTEXAS32016
MauriceLOUISIANA22013
KaplanLOUISIANA22014
Ltl ChenierLOUISIANA22013
Ville PlatteLOUISIANA22019
Hackberry 2LOUISIANA22024
Forked Island 2LOUISIANA22010
Lag AtascosaTEXAS22024
IndianolaTEXAS22014
Port AcresTEXAS22017
McfaddinTEXAS22016
Gran ChenierLOUISIANA11982
HackberryLOUISIANA12011
EstherLOUISIANA12019
RichardLOUISIANA12023
Sabine NwrLOUISIANA12008
WoodlawnLOUISIANA12021
Hinkles FerTEXAS11979

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