BirdAnalyst
Species · Vermont · BBS 2025 Release · 1966–2024

Mourning Warbler Population Trend in Vermont

All statesForest birds

Mourning Warbler in Vermont has surged: up 502% on the route-weighted index since 1969.

+502%Since 1969
25Routes In State
51Years

Notable Mourning Warbler Trends in Vermont

long arc increasecomputed index

Mourning Warbler has surged in Vermont: up 502% on the route-weighted index since 1969.

Mourning Warbler Population Forecast in Vermont

If the recent trend holds, Mourning Warbler in Vermont is projected to rise about 93% by 2029 — from 0.33 in 2024 to a central estimate of 0.64 (95% range 0.14–1.1). A 5-year backtest shows a typical error of ±156.4%, with 80% of held-out values landing inside the 95% band.

+93%Change by 2029
0.64Projected 2029 index
0.14–1.195% range
±156.4%Backtest error
19672029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20250.620.111.1
20260.620.121.1
20270.630.121.1
20280.640.131.1
20290.640.141.1

Mourning Warbler Survey Routes in Vermont

Routes recording Mourning Warbler in Vermont.
Gaysville220091980
S Wallingfrd219911991
East Haven220241980
Hardwick220241980
Waterville219801973
Newbury 2220232010
North Pownal119921992
Stratton120071997
Landgrove120221969
S Reading120001975
Post Mills120111977
Shaftsbury120001988
W Rutland120241989
St Johnsbury120241971
Northfld Fls120181980
Middlesex120221977
East Calais120221975
Newbury120041988
Greensboro120211967
Fletcher120231983
Hinesburg119901990
Colchester119901990
Grand Isle119971989
Stowe120231990
Bristol119961996

Mourning Warbler Population Trend in Other States

connecticutillinoisindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-yorknorth-dakotaohiopennsylvaniawest-virginiawisconsin

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