BirdAnalyst
Species · Massachusetts · BBS 2026 Release · 1966–2025

Common Grackle Population Trend in Massachusetts

All statesGeneralists

Common Grackle in Massachusetts has collapsed: down 76% on the route-weighted index since 1968.

-76%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 →
32Routes 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 →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Common Grackle 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 declinecomputed 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 →

Common Grackle has collapsed in Massachusetts: down 76% on the route-weighted index since 1968.

Common Grackle Population Forecast in Massachusetts

If the recent trend holds, Common Grackle in Massachusetts is projected to fall about 45% by 2030 — from 13 in 2025 to a central estimate of 6.9 (95% range 0.00–21). A 5-year backtest shows a typical error of ±39%, with 100% of held-out values landing inside the 95% band.

-45%Change by 2030TrendPercent 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 →
6.9Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–2195% 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 →
±39%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, Common Grackle in Massachusetts is projected to fall about 45% by 2030 — from 13 in 2025 to a central estimate of 6.9 (95% range 0.00–21). A 5-year backtest shows a typical error of ±39%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20269.50.0024
20278.90.0023
20288.20.0022
20297.60.0022
20306.90.0021

Common Grackle Survey Routes in Massachusetts

Routes recording Common Grackle 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 →
Chilmark5419831969
Cheshire4219941969
E Pepperell3719941966
Gay Head3020251996
Newburyport2820221967
Mansfield2720251968
Wellfleet2520071966
Wellfleet 22520252016
Warren 22420252010
Cape Cod Ns2220071989
Prattville1920191966
E Dennis1720211967
Brockton1720191967
Marion1620251966
Princeton1519761969
Monterey1220252019
N Oxford1120251968
Belchertown1120251967
Maynard1020251967
Holden1020251977
N. Andover1020251995
Cummington920141968
Ware River920221993
Warren720091968
S Barre620251968

Common Grackle Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.