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Species · North Carolina · BBS 2026 Release · 1966–2025

Boat-tailed Grackle Population Trend in North Carolina

All statesWetland birds

Boat-tailed Grackle in North Carolina has increased: up 38% on the route-weighted index since 1969.

+38%Since 1969TrendPercent 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 →
19Routes In StateSurvey 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 Boat-tailed Grackle Trends in North CarolinaNotable 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 Boat-tailed Grackle in North Carolina. See the full index history below.

Boat-tailed Grackle Population Forecast in North Carolina

If the recent trend holds, Boat-tailed Grackle in North Carolina is projected to rise about 69% by 2030 — from 0.74 in 2025 to a central estimate of 1.2 (95% range 0.00–2.9). A 5-year backtest shows a typical error of ±253.6%, with 100% of held-out values landing inside the 95% band.

+69%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 →
1.2Projected 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 →
0.00–2.995% 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 →
±253.6%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, Boat-tailed Grackle in North Carolina is projected to rise about 69% by 2030 — from 0.74 in 2025 to a central estimate of 1.2 (95% range 0.00–2.9). A 5-year backtest shows a typical error of ±253.6%, 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 →
20261.30.002.9
20271.30.002.9
20281.30.002.9
20291.30.002.9
20301.20.002.9

Boat-tailed Grackle Survey Routes in North Carolina

Routes recording Boat-tailed Grackle in North Carolina.
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 →
Jarvisburg3619991992
Myrtle Grove2020251966
Shallotte1719911983
Merrimon1220231968
Milltail Cr1120251992
Jarvisburg 2820252000
Supply520251992
Chowan River420062003
Grandy419751971
Belgrade420192019
Green Swamp320062006
Rheasville320062006
Ernul320092009
Old Trap220172017
Newport220231995
Mashoes119821982
Broad Creek120251993
Kinston119681968
Cayton120172010

Boat-tailed Grackle Population Trend in Other States

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