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

Mourning Warbler Population Trend in New York

All statesForest birds

Mourning Warbler in New York has increased: up 40% on the route-weighted index since 1968.

+40%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 →
88Routes 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 →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Mourning Warbler Trends in New YorkNotable 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 Mourning Warbler in New York. See the full index history below.

Mourning Warbler Population Forecast in New York

If the recent trend holds, Mourning Warbler in New York is projected to fall about 23% by 2030 — from 0.83 in 2025 to a central estimate of 0.64 (95% range 0.26–1.0). A 5-year backtest shows a typical error of ±43.2%, with 100% of held-out values landing inside the 95% band.

-23%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 →
0.64Projected 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 →
0.26–1.095% 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 →
±43.2%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, Mourning Warbler in New York is projected to fall about 23% by 2030 — from 0.83 in 2025 to a central estimate of 0.64 (95% range 0.26–1.0). A 5-year backtest shows a typical error of ±43.2%, 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 →
20260.640.261.0
20270.640.261.0
20280.640.261.0
20290.640.261.0
20300.640.261.0

Mourning Warbler Survey Routes in New York

Routes recording Mourning Warbler in New York.
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 →
Old Forge1119961971
Highmarket920251975
Wanakena620251980
Mcdonough520171970
Dexter Lake519691968
Sheridan420251968
Alder Creek420041976
Blue Ridge N320251980
North River320251971
Parishville320251997
Milford320221980
N Victory319721967
St Regis Fls320171976
Duanesburg220182018
E Newark219961996
Romulus219751975
Dryden220211979
Orleans220152015
Cattaraugus220191967
East Java220181967
N Victory 2220021978
N Wilmurt219981968
Newcomb220191986
Degrasse220251980
Sabattis219831966

Mourning Warbler Population Trend in Other States

connecticutillinoisindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenorth-dakotaohiopennsylvaniavermontwest-virginiawisconsin

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