BirdAnalyst
Species · New Jersey · BBS 2026 Release · 1966–2025

Glossy Ibis Population Trend in New Jersey

All statesWetland birds

Glossy Ibis in New Jersey has surged: up 606% on the route-weighted index since 1971.

+606%Since 1971TrendPercent 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 →
11Routes 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 →
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 Glossy Ibis 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 →

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 →

Glossy Ibis has surged in New Jersey: up 606% on the route-weighted index since 1971.

Glossy Ibis Population Forecast in New Jersey

If the recent trend holds, Glossy Ibis in New Jersey is projected to fall about 100% by 2030 — from 0.06 in 2025 to a central estimate of 0.00 (95% range 0.00–8.3). A 5-year backtest shows a typical error of ±359.8%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–8.395% 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 →
±359.8%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, Glossy Ibis in New Jersey is projected to fall about 100% by 2030 — from 0.06 in 2025 to a central estimate of 0.00 (95% range 0.00–8.3). A 5-year backtest shows a typical error of ±359.8%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20260.000.008.3
20270.000.008.3
20280.000.008.3
20290.000.008.3
20300.000.008.3

Glossy Ibis Survey Routes in New Jersey

Routes recording Glossy Ibis 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 →
Villas4119811979
Del Haven1719911991
Spraguetown319911991
Six Points320151980
Cape May Ch320131992
Pomona219801980
Greenwich120051969
Deepwater119711970
Toms River119971997
Spraguetown 2120012001
Ocean City120251979

Glossy Ibis Population Trend in Other States

alabamaconnecticutdelawarefloridageorgialouisianamainemarylandmassachusettsnew-hampshirenew-yorknorth-carolinarhode-islandsouth-carolinasouth-dakotatexasvirginia

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