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

Broad-winged Hawk Population Trend in Vermont

All statesGeneralists

Broad-winged Hawk in Vermont has surged: up 216% on the route-weighted index since 1968.

+216%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 →
54YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Broad-winged Hawk 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 →

Broad-winged Hawk has surged in Vermont: up 216% on the route-weighted index since 1968.

Broad-winged Hawk Population Forecast in Vermont

If the recent trend holds, Broad-winged Hawk in Vermont is projected to fall about 26% by 2029 — from 0.44 in 2024 to a central estimate of 0.33 (95% range 0.09–0.56). A 5-year backtest shows a typical error of ±47.3%, with 80% of held-out values landing inside the 95% band.

-26%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 →
0.33Projected 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 →
0.09–0.5695% 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 →
±47.3%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, Broad-winged Hawk in Vermont is projected to fall about 26% by 2029 — from 0.44 in 2024 to a central estimate of 0.33 (95% range 0.09–0.56). A 5-year backtest shows a typical error of ±47.3%, with 80% 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 →
20250.320.080.55
20260.320.080.55
20270.320.090.56
20280.330.090.56
20290.330.090.56

Broad-winged Hawk Survey Routes in Vermont

Routes recording Broad-winged Hawk 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 →
Stratton220241978
Landgrove220231974
S Reading220241971
Middlesex220241968
East Calais220191966
Stowe220221991
Marlboro120161995
North Pownal120222022
Gaysville120181978
Post Mills120151980
Shaftsbury120231975
S Wallingfrd120221981
W Rutland120221979
St Johnsbury120211973
East Haven120241975
Northfld Fls120211986
Newbury120041998
Hardwick120241966
Greensboro120151967
Fletcher120161993
Waterville119671967
Hinesburg119931993
Colchester120211995
Grand Isle119871987
Newbury 2120222005

Broad-winged Hawk Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvirginiawest-virginiawisconsinwyoming

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