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Species · Massachusetts · BBS 2025 Release · 1966–2024

Blue-headed Vireo Population Trend in Massachusetts

All statesForest birds

Blue-headed Vireo in Massachusetts has surged: up 994% on the route-weighted index since 1969.

+994%Since 1969TrendPercent 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 →
22Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Blue-headed Vireo Trends in MassachusettsNotable 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 →

Blue-headed Vireo has surged in Massachusetts: up 993% on the route-weighted index since 1969.

Blue-headed Vireo Population Forecast in Massachusetts

If the recent trend holds, Blue-headed Vireo in Massachusetts is projected to rise about 122% by 2029 — from 0.73 in 2024 to a central estimate of 1.6 (95% range 0.72–2.5). A 5-year backtest shows a typical error of ±50.5%, with 100% of held-out values landing inside the 95% band.

+122%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 →
1.6Projected 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 →
0.72–2.595% 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 →
±50.5%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, Blue-headed Vireo in Massachusetts is projected to rise about 122% by 2029 — from 0.73 in 2024 to a central estimate of 1.6 (95% range 0.72–2.5). A 5-year backtest shows a typical error of ±50.5%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20251.60.652.5
20261.60.672.5
20271.60.692.5
20281.60.702.5
20291.60.722.5

Blue-headed Vireo Survey Routes in Massachusetts

Routes recording Blue-headed Vireo in Massachusetts.
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 →
Cummington720141969
Sheffield720221969
Princeton519761972
Cummington 2420242015
Chesterfield320241967
Newburyport219791979
Belchertown220231973
S Barre220231971
Monterey220242019
Ware River120221993
Prattville119991997
Littleton120081975
N Oxford120122012
Mansfield119871987
E Pepperell119871983
Warren120081975
N Orange120241968
Cheshire119921982
Pittsfield120161969
Holden120241978
Warren 2120232023
Hancock120151997

Blue-headed Vireo Population Trend in Other States

alabamaconnecticutgeorgiakentuckymainemarylandmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiopennsylvaniarhode-islandsouth-carolinatennesseevermontvirginiawest-virginiawisconsin

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