BirdAnalyst
Species · Vermont · BBS 2025 Release · 1966–2024

Osprey Population Trend in Vermont

All statesGeneralists

Osprey in Vermont has surged: up 292% on the route-weighted index since 1999.

+292%Since 1999TrendPercent 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 →
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 VermontNotable 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 Vermont: up 292% on the route-weighted index since 1999.

Osprey Population Forecast in Vermont

If the recent trend holds, Osprey in Vermont is projected to stay roughly flat through 2029, near 0.36 (95% range 0.15–0.57). A 5-year backtest shows a typical error of ±99.3%, with 40% of held-out values landing inside the 95% band.

-7%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 →
0.36Projected 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 →
0.15–0.5795% 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 →
±99.3%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 Vermont is projected to stay roughly flat through 2029, near 0.36 (95% range 0.15–0.57). A 5-year backtest shows a typical error of ±99.3%, with 40% of held-out values landing inside the 95% band.19902029
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 →
20250.340.130.55
20260.340.130.55
20270.350.140.56
20280.360.150.56
20290.360.150.57

Osprey Survey Routes in Vermont

Routes recording Osprey in Vermont.
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 →
Grand Isle720241998
North Pownal120162016
Gaysville120122012
St Johnsbury119901990
Fletcher120222014
Bristol119991999

Osprey Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvirginiawashingtonwest-virginiawisconsinwyoming

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