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Species · Maryland · BBS 2025 Release · 1966–2024

Glossy Ibis Population Trend in Maryland

All statesWetland birds

Glossy Ibis in Maryland has surged: up 804% on the route-weighted index since 1968.

+804%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 →
13Routes 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 →
53YearsYears 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 MarylandNotable 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 Maryland: up 804% on the route-weighted index since 1968.

Glossy Ibis Population Forecast in Maryland

If the recent trend holds, Glossy Ibis in Maryland is projected to rise about 246% by 2029 — from 0.21 in 2024 to a central estimate of 0.74 (95% range 0.00–2.1). A 5-year backtest shows a typical error of ±110.3%, with 100% of held-out values landing inside the 95% band.

+246%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 →
0.74Projected 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 →
0.00–2.195% 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 →
±110.3%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, Glossy Ibis in Maryland is projected to rise about 246% by 2029 — from 0.21 in 2024 to a central estimate of 0.74 (95% range 0.00–2.1). A 5-year backtest shows a typical error of ±110.3%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.710.002.1
20260.720.002.1
20270.730.002.1
20280.730.002.1
20290.740.002.1

Glossy Ibis Survey Routes in Maryland

Routes recording Glossy Ibis in Maryland.
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 →
Golden Hill2519721972
Pomfret1519941994
Berlin1120211980
Furnace Town720182018
Honga620241972
Sinepuxent419751966
Indiantown320041989
Madison220241974
Snow Hill219761970
Elkton120161971
Grove Neck119951995
Cokesbury120211983
Newark120241966

Glossy Ibis Population Trend in Other States

alabamaconnecticutdelawarefloridageorgialouisianamainemassachusettsnew-hampshirenew-jerseynew-yorknorth-carolinarhode-islandsouth-carolinasouth-dakotatexasvirginia

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