BirdAnalyst
Species · Maryland · BBS 2026 Release · 1966–2025

King Rail Population Trend in Maryland

All statesWetland birds

King Rail in Maryland has surged: up 86% on the route-weighted index since 1975.

+86%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 →
5Routes 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 →
26YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable King Rail 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 →

No notable trend signals for King Rail in Maryland. See the full index history below.

King Rail Population Forecast in Maryland

If the recent trend holds, King Rail in Maryland is projected to stay roughly flat through 2030, near 0.04 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±36.6%, with 60% of held-out values landing inside the 95% band.

n/aChange 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 →
0.04Projected 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 →
0.00–0.0895% 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 →
±36.6%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, King Rail in Maryland is projected to stay roughly flat through 2030, near 0.04 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±36.6%, with 60% of held-out values landing inside the 95% band.19732030
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 →
20260.040.000.08
20270.040.000.08
20280.040.000.08
20290.040.000.08
20300.040.000.08

King Rail Survey Routes in Maryland

Routes recording King Rail 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 →
Honga220241973
Melitota119741974
Golden Hill119751975
Madison120251976
Cokesbury119731973

King Rail Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiakansaslouisianaminnesotamississippinew-jerseynorth-carolinaoklahomasouth-carolinatexasvirginiawest-virginiawisconsin

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