BirdAnalyst
Species · BCR 22 · BBS 2026 Release · 1966–2025

Common Grackle In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGeneralists

Common Grackle in Eastern Tallgrass Prairie has fallen sharply: down 72% on the route-weighted index since 1968.

-72%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 →
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 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 72% 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 44% by 2030 — from 28 in 2025 to a central estimate of 40 (95% range 16–65). A 5-year backtest shows a typical error of ±85.3%, with 0% of held-out values landing inside the 95% band.

+44%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 →
40Projected 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 →
16–6595% 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 →
±85.3%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 44% by 2030 — from 28 in 2025 to a central estimate of 40 (95% range 16–65). A 5-year backtest shows a typical error of ±85.3%, with 0% 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 →
2026452069
2027441968
2028421867
2029411766
2030401665

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 →
HarveysburgOHIO3911996
WilmingtonOHIO2871996
NewportOHIO2741994
AtkinsonILLINOIS2502024
W CarrolltonOHIO2092015
BrookvilleINDIANA1842025
PlainfieldINDIANA1711999
GridleyILLINOIS1682025
TecumsehOHIO1531982
Sni MillsMISSOURI1461990
TiptonINDIANA1431992
StreatorILLINOIS1332025
FairburyILLINOIS1332025
BeaucoupILLINOIS1292025
DecaturINDIANA1212025
FairlandILLINOIS1192025
DunlapOHIO1171988
MonticelloILLINOIS1152025
MilroyINDIANA1132025
DesmoinesIOWA1101979
GretnaNEBRASKA1082018
EssexILLINOIS1032025
Kings CreekOHIO992015
Le RoyILLINOIS982025
ThrallKANSAS971970

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