BirdAnalyst
Species · New Hampshire · BBS 2025 Release · 1966–2024

Yellow Warbler Population Trend in New Hampshire

All statesForest birds

Yellow Warbler in New Hampshire has held roughly steady: up 7% on the route-weighted index since 1968.

+7%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 →
25Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow Warbler Trends in New HampshireNotable 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 Yellow Warbler in New Hampshire. See the full index history below.

Yellow Warbler Population Forecast in New Hampshire

If the recent trend holds, Yellow Warbler in New Hampshire is projected to stay roughly flat through 2029, near 3.7 (95% range 1.4–5.9). A 5-year backtest shows a typical error of ±8.5%, with 100% of held-out values landing inside the 95% band.

-6%Change 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 →
3.7Projected 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 →
1.4–5.995% 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 →
±8.5%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, Yellow Warbler in New Hampshire is projected to stay roughly flat through 2029, near 3.7 (95% range 1.4–5.9). A 5-year backtest shows a typical error of ±8.5%, 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 →
20253.81.56.0
20263.71.56.0
20273.71.55.9
20283.71.55.9
20293.71.45.9

Yellow Warbler Survey Routes in New Hampshire

Routes recording Yellow Warbler in New Hampshire.
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 →
Fitzwilliam1120241966
Canterbury1120241966
Milan1120241966
Dover720241966
Concord620241966
Stratford620241966
East Kingston520241999
Brentwood419981966
Mt Chocorua420241970
Walpole420241966
Marlow420241966
Strafford320241966
Jefferson Hl320241966
Lempster220241969
Glen220241976
Peterborough120231966
Hopkinton120241966
Epsom120211966
Gilmantn I W120241969
Wilmot120241966
Franconia120041966
Dixvil Notch120171966
Clarksville120241974
Jeffers Ntch120241993
Dixville Notch 2120242019

Yellow Warbler Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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