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

Common Grackle Population Trend in Massachusetts

All statesGeneralists

Common Grackle in Massachusetts has collapsed: down 75% on the route-weighted index since 1968.

-75%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 →
58YearsYears 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 75% 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 53% by 2029 — from 16 in 2024 to a central estimate of 7.4 (95% range 0.00–22). A 5-year backtest shows a typical error of ±37.4%, with 100% of held-out values landing inside the 95% band.

-53%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 →
7.4Projected 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 →
0.00–2295% 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 →
±37.4%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 53% by 2029 — from 16 in 2024 to a central estimate of 7.4 (95% range 0.00–22). A 5-year backtest shows a typical error of ±37.4%, with 100% 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 →
2025100.0024
20269.40.0024
20278.70.0023
20288.00.0022
20297.40.0022

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
Mansfield5220241968
Cheshire4219941969
E Pepperell3719941966
Wellfleet 23020242016
Newburyport2820221967
Warren 22620242010
Wellfleet2520071966
N Oxford2220241968
Cape Cod Ns2220071989
N. Andover2020241995
Prattville1920191966
Marion1820241966
E Dennis1720211967
Brockton1720191967
Chesterfield1620241967
Princeton1519761969
Belchertown1220241967
Cummington920141968
Ware River920221993
N Orange820241968
Holden820241977
Warren720091968
S Barre720241968
Gay Head720241996

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 2026-05-22.