BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Tennessee Warbler

ParulidaeForest birdsLeiothlypis peregrina

Tennessee Warbler has surged: up 76% on the route-weighted index since 1968.

+76%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 →
175RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Tennessee Warbler

The Tennessee Warbler (Leiothlypis peregrina) is a North American member of the Wood-Warblers (Parulidae). In this analysis it is grouped with the forest birds.

Size
4.5–5.5 in long (11–14 cm) — a small, active songbird (typical for the family)
Habitat
Woodlands and forest edges, including wooded suburbs and parks.
Diet
Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
Range
Recorded on 175 Breeding Bird Survey routes across 10 states, most concentrated in the Atlantic Northern Forest.
Family
Parulidae · Forest birds

Notable Tennessee Warbler TrendsNotable 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 Tennessee Warbler. See the full index history below.

Tennessee Warbler Population Forecast

If the recent trend holds, Tennessee Warbler is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.03). A 5-year backtest shows a typical error of ±57.5%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.01Projected 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 →
0.00–0.0395% 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 →
±57.5%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, Tennessee Warbler is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.03). A 5-year backtest shows a typical error of ±57.5%, 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 →
20250.010.000.03
20260.010.000.03
20270.010.000.03
20280.010.000.03
20290.010.000.03

Where the Tennessee Warbler Is Detected

BBS routes recording Tennessee Warbler, sized by most recent count.

Tennessee Warbler Population Trend by State

Tennessee Warbler population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Alaska-90%199516
Maine-87%197160
Michigan-38%197126
Minnesota+18%197130
Montana+12%19886
New Hampshire-9%196810
New York+135%197610
Pennsylvaniainsufficient datan/a1
Vermontinsufficient datan/a5
Wisconsin-25%198411

Tennessee Warbler Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Tennessee Warbler population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
BCR 4-80%199511
Northern Rockies+20%19886
Boreal Hardwood Transition+163%197062
Atlantic Northern Forest-63%196884
Prairie Hardwood Transition-44%19965

Tennessee Warbler Conservation Status

Our route-weighted index shows it up about 76% since 1968.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.