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

Lincoln's Sparrow Population Trend in New Hampshire

All statesGeneralists

Lincoln's Sparrow in New Hampshire has fallen sharply: down 75% on the route-weighted index since 1968.

-75%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 →
6Routes 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 Lincoln's Sparrow 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 →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Lincoln's Sparrow has fallen sharply in New Hampshire: down 75% on the route-weighted index since 1968.

Lincoln's Sparrow Population Forecast in New Hampshire

If the recent trend holds, Lincoln's Sparrow in New Hampshire is projected to fall about 71% by 2029 — from 0.14 in 2024 to a central estimate of 0.04 (95% range 0.00–0.48). A 5-year backtest shows a typical error of ±43.7%, with 100% of held-out values landing inside the 95% band.

-71%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 →
0.04Projected 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 →
0.00–0.4895% 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 →
±43.7%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, Lincoln's Sparrow in New Hampshire is projected to fall about 71% by 2029 — from 0.14 in 2024 to a central estimate of 0.04 (95% range 0.00–0.48). A 5-year backtest shows a typical error of ±43.7%, 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 →
20250.070.000.51
20260.070.000.50
20270.060.000.49
20280.050.000.49
20290.040.000.48

Lincoln's Sparrow Survey Routes in New Hampshire

Routes recording Lincoln's Sparrow 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 →
Dixville Notch 2320242018
Dixvil Notch220171966
Franconia119941980
Milan120101970
Stratford119981967
Clarksville120121969

Lincoln's Sparrow Population Trend in Other States

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