Species · Connecticut · BBS 2025 Release · 1966–2024

Chestnut-sided Warbler Population Trend in Connecticut

Chestnut-sided Warbler in Connecticut has fallen sharply: down 62% on the route-weighted index since 1968.

-62%Since 1968
20Routes In State
58Years

Notable Chestnut-sided Warbler Trends in Connecticut

long arc declinecomputed index

Chestnut-sided Warbler has fallen sharply in Connecticut: down 62% on the route-weighted index since 1968.

Chestnut-sided Warbler Population Forecast in Connecticut

If the recent trend holds, Chestnut-sided Warbler in Connecticut is projected to rise about 25% by 2029 — from 2.6 in 2024 to a central estimate of 3.2 (95% range 0.00–6.9). A 5-year backtest shows a typical error of ±60.1%, with 100% of held-out values landing inside the 95% band.

+25%Change by 2029
3.2Projected 2029 index
0.006.995% range
±60.1%Backtest error
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 index95% low95% high
20253.40.007.1
20263.30.007.0
20273.30.007.0
20283.20.006.9
20293.20.006.9

Chestnut-sided Warbler Survey Routes in Connecticut

Routes recording Chestnut-sided Warbler in Connecticut.
Warren2920111972
Woodstock 2820242017
Granby720241988
New Hartford519871972
E Hartland419921966
Woodstock420071968
Warren 2420242012
No Woodbury320241967
Sherman220191972
Long Hill220171974
Mystic120011973
Buckingham120211966
Uncasville120211973
Westbrook119991978
Willimantic120181967
Greenwich119971967
Danbury120191968
Mid Haddam120221973
Southington120231973
New Hartford120241994

Chestnut-sided Warbler Population Trend in Other States

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