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

Osprey Population Trend in New Hampshire

All statesGeneralists

Osprey in New Hampshire has surged: up 147% on the route-weighted index since 1991.

+147%Since 1991TrendPercent 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 →
14Routes 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 →
22YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Osprey 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 increasecomputed 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 →

Osprey has surged in New Hampshire: up 147% on the route-weighted index since 1991.

Osprey Population Forecast in New Hampshire

If the recent trend holds, Osprey in New Hampshire is projected to rise about 41% by 2028 — from 0.09 in 2023 to a central estimate of 0.12 (95% range 0.06–0.19). A 5-year backtest shows a typical error of ±23.4%, with 80% of held-out values landing inside the 95% band.

+41%Change by 2028TrendPercent 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 →
0.12Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.06–0.1995% 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 →
±23.4%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, Osprey in New Hampshire is projected to rise about 41% by 2028 — from 0.09 in 2023 to a central estimate of 0.12 (95% range 0.06–0.19). A 5-year backtest shows a typical error of ±23.4%, with 80% of held-out values landing inside the 95% band.19742028
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 →
20240.120.050.18
20250.120.050.18
20260.120.050.18
20270.120.060.19
20280.120.060.19

Osprey Survey Routes in New Hampshire

Routes recording Osprey 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 →
Dover220212000
Hopkinton120232013
Epsom119911991
Concord120212016
Strafford120182018
East Kingston120172014
Mt Chocorua119971997
Walpole120131980
Lempster120222022
Jefferson Hl119741974
Milan120231994
Stratford120111998
Jeffers Ntch120162016
Clarksville120222022

Osprey Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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