BirdAnalyst
Species · New Jersey · BBS 2025 Release · 1966–2024

Boat-tailed Grackle Population Trend in New Jersey

All statesGeneralists

Boat-tailed Grackle in New Jersey has edged up: up 25% on the route-weighted index since 1981.

+25%Since 1981TrendPercent 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 →
4Routes 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 →
41YearsYears 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 New JerseyNotable 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 New Jersey. See the full index history below.

Boat-tailed Grackle Population Forecast in New Jersey

If the recent trend holds, Boat-tailed Grackle in New Jersey is projected to stay roughly flat through 2029, near 1.4 (95% range 0.00–4.4). A 5-year backtest shows a typical error of ±797.8%, with 100% of held-out values landing inside the 95% band.

-6%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 →
1.4Projected 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 →
0.00–4.495% 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 →
±797.8%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 New Jersey is projected to stay roughly flat through 2029, near 1.4 (95% range 0.00–4.4). A 5-year backtest shows a typical error of ±797.8%, with 100% of held-out values landing inside the 95% band.19792029
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 →
20251.50.004.4
20261.50.004.4
20271.50.004.4
20281.50.004.4
20291.40.004.4

Boat-tailed Grackle Survey Routes in New Jersey

Routes recording Boat-tailed Grackle in New Jersey.
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 →
Ocean City2320241979
Six Points920241989
Toms River119981998
Cape May Ch120042001

Boat-tailed Grackle Population Trend in Other States

alabamadelawarefloridageorgialouisianamarylandmississippinew-yorknorth-carolinasouth-carolinatexasvirginia

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