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

Common Grackle Population Trend in Maryland

All statesGeneralists

Common Grackle in Maryland has collapsed: down 77% on the route-weighted index since 1968.

-77%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 →
76Routes 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 MarylandNotable 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 Maryland: down 77% on the route-weighted index since 1968.

Common Grackle Population Forecast in Maryland

If the recent trend holds, Common Grackle in Maryland is projected to fall about 43% by 2029 — from 45 in 2024 to a central estimate of 26 (95% range 0.00–52). A 5-year backtest shows a typical error of ±8.6%, with 100% of held-out values landing inside the 95% band.

-43%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 →
26Projected 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 →
0.00–5295% 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 →
±8.6%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 Maryland is projected to fall about 43% by 2029 — from 45 in 2024 to a central estimate of 26 (95% range 0.00–52). A 5-year backtest shows a typical error of ±8.6%, 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 →
2025347.761
2026325.659
2027303.456
2028281.354
2029260.0052

Common Grackle Survey Routes in Maryland

Routes recording Common Grackle in Maryland.
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 →
Harmony26420171966
Matthews25720241966
Williamsport24220241966
Fruitland18119981966
Sinepuxent16019781966
Cokesbury14920241966
Tall Timbers14520141966
Snow Hill14219761966
Melitota11120241966
Broomes Isl10419961966
Piney Neck10020241966
Grove Neck10019961992
Vienna8420241966
Newark7920241966
Emmitsburg7520241966
Bald Friar7519961992
Millington7220241966
Fair Hill7219961992
Easton7020211966
Cheltenham6720041966
Pt Republic6519891966
Forest Grove5820232011
Largo5519811966
Pr Frederick5420241991
Jennings5320241995

Common Grackle Population Trend in Other States

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

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