BirdAnalyst
Species · BCR 29 · BBS 2025 Release · 1966–2024

Common Grackle In Piedmont

All regionsPiedmontGeneralists

Common Grackle in Piedmont has collapsed: down 86% on the route-weighted index since 1968.

-86%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 →
172Routes In RegionSurvey 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 SignalsNotable 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 Piedmont: down 86% on the route-weighted index since 1968.

Common Grackle In Piedmont Population Forecast

If the recent trend holds, Common Grackle in Piedmont is projected to fall about 100% by 2029 — from 16 in 2024 to a central estimate of 0.00 (95% range 0.00–24). A 5-year backtest shows a typical error of ±83.4%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–2495% 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 →
±83.4%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 Piedmont is projected to fall about 100% by 2029 — from 16 in 2024 to a central estimate of 0.00 (95% range 0.00–24). A 5-year backtest shows a typical error of ±83.4%, 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 →
20251.00.0025
20260.000.0024
20270.000.0024
20280.000.0024
20290.000.0024

Routes In Piedmont

Routes recording Common Grackle in Piedmont.
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 →
AkronPENNSYLVANIA4041997
Sporting HilPENNSYLVANIA2291977
AspersPENNSYLVANIA1911989
PottstownPENNSYLVANIA1831987
Mt GretnaPENNSYLVANIA1582000
LabottPENNSYLVANIA1501983
LeolaPENNSYLVANIA1412024
Rock BranchGEORGIA1342024
GatchelvillePENNSYLVANIA1321990
EphrataPENNSYLVANIA1211988
PendletonSOUTH-CAROLINA1211976
West GrovePENNSYLVANIA1001996
Mt Gretna 2PENNSYLVANIA872022
Mount JoyPENNSYLVANIA812024
PassaicNEW-JERSEY801969
CherryvilleNORTH-CAROLINA771968
EmmitsburgMARYLAND752024
Bald FriarMARYLAND751996
MetasvilleGEORGIA702000
DavidVIRGINIA692013
Boiling SpgsSOUTH-CAROLINA661979
Brandy StationVIRGINIA642024
WilgroveNORTH-CAROLINA552023
AppomattoxVIRGINIA512024
MadisonNORTH-CAROLINA491985

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