BirdAnalyst
Species · BCR 22 · BBS 2025 Release · 1966–2024

Common Grackle In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGeneralists

Common Grackle in Eastern Tallgrass Prairie has fallen sharply: down 71% on the route-weighted index since 1968.

-71%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 →
278Routes 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 fallen sharply in Eastern Tallgrass Prairie: down 71% on the route-weighted index since 1968.

Common Grackle In Eastern Tallgrass Prairie Population Forecast

If the recent trend holds, Common Grackle in Eastern Tallgrass Prairie is projected to rise about 37% by 2029 — from 31 in 2024 to a central estimate of 43 (95% range 18–67). A 5-year backtest shows a typical error of ±82.9%, with 0% of held-out values landing inside the 95% band.

+37%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 →
43Projected 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 →
18–6795% 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 →
±82.9%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 Eastern Tallgrass Prairie is projected to rise about 37% by 2029 — from 31 in 2024 to a central estimate of 43 (95% range 18–67). A 5-year backtest shows a typical error of ±82.9%, with 0% 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 →
2025472371
2026462270
2027452169
2028442068
2029431867

Routes In Eastern Tallgrass Prairie

Routes recording Common Grackle in Eastern Tallgrass Prairie.
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 →
MilroyINDIANA4142024
HarveysburgOHIO3911996
WilmingtonOHIO2871996
NewportOHIO2741994
AtkinsonILLINOIS2502024
W CarrolltonOHIO2092015
Marion 2OHIO2022024
PlainfieldINDIANA1711999
FairburyILLINOIS1592024
TecumsehOHIO1531982
PontiacILLINOIS1472024
Sni MillsMISSOURI1461990
GridleyILLINOIS1442024
TiptonINDIANA1431992
MonticelloILLINOIS1362024
StreatorILLINOIS1222024
DunlapOHIO1171988
DesmoinesIOWA1101979
GretnaNEBRASKA1082018
KalidaOHIO1062019
Witts StationINDIANA1042024
Kings CreekOHIO992015
ShelbyvilleINDIANA972024
ThrallKANSAS971970
Ash CreekMINNESOTA942024

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