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

Osprey Population Trend in Connecticut

All statesGeneralists

Osprey in Connecticut has surged: up 245% on the route-weighted index since 1990.

+245%Since 1990TrendPercent 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 →
31YearsYears 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 ConnecticutNotable 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 Connecticut: up 245% on the route-weighted index since 1990.

Osprey Population Forecast in Connecticut

If the recent trend holds, Osprey in Connecticut is projected to fall about 33% by 2029 — from 0.56 in 2024 to a central estimate of 0.37 (95% range 0.13–0.62). A 5-year backtest shows a typical error of ±80.7%, with 80% of held-out values landing inside the 95% band.

-33%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 →
0.37Projected 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 →
0.13–0.6295% 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 →
±80.7%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, Osprey in Connecticut is projected to fall about 33% by 2029 — from 0.56 in 2024 to a central estimate of 0.37 (95% range 0.13–0.62). A 5-year backtest shows a typical error of ±80.7%, with 80% of held-out values landing inside the 95% band.19812029
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 →
20250.350.100.60
20260.350.110.60
20270.360.110.61
20280.370.120.61
20290.370.130.62

Osprey Survey Routes in Connecticut

Routes recording Osprey in Connecticut.
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 →
Westbrook420241994
Mystic120231986
Uncasville120141990
Greenwich120092009
Warren120101986
Mid Haddam120241981

Osprey Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradodelawarefloridageorgiaidahoillinoisindianaiowakentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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