BirdAnalyst
Species · BCR 23 · BBS 2026 Release · 1966–2025

Common Grackle In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionGeneralists

Common Grackle in Prairie Hardwood Transition has fallen sharply: down 63% on the route-weighted index since 1968.

-63%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 →
161Routes 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 Prairie Hardwood Transition: down 63% on the route-weighted index since 1968.

Common Grackle In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Common Grackle in Prairie Hardwood Transition is projected to fall about 41% by 2030 — from 22 in 2025 to a central estimate of 13 (95% range 0.00–35). A 5-year backtest shows a typical error of ±17.1%, with 100% of held-out values landing inside the 95% band.

-41%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 →
13Projected 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 →
0.00–3595% 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 →
±17.1%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 Prairie Hardwood Transition is projected to fall about 41% by 2030 — from 22 in 2025 to a central estimate of 13 (95% range 0.00–35). A 5-year backtest shows a typical error of ±17.1%, with 100% 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 →
2026180.0040
2027170.0039
2028150.0038
2029140.0036
2030130.0035

Routes In Prairie Hardwood Transition

Routes recording Common Grackle in Prairie Hardwood Transition.
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 →
BismarkOHIO1961995
Cherry ValILLINOIS1242003
South BendINDIANA1201991
GraytownOHIO1101984
New LondonMINNESOTA1032024
NapoleonOHIO1032025
PettysvilleMICHIGAN941979
OmroWISCONSIN822001
VickeryOHIO802025
Mount HorebWISCONSIN781990
S LyonsMICHIGAN771992
Pt WashingtnWISCONSIN762024
WeyerhauserWISCONSIN752025
TrempealeauWISCONSIN752025
AnnatonWISCONSIN752025
WhitewaterMINNESOTA732000
RichmondMICHIGAN672024
LockportOHIO672025
EdenWISCONSIN652025
North BranchMICHIGAN641999
Drayton PlnsMICHIGAN641987
PackertownINDIANA582004
Whitewater 2MINNESOTA562019
GrimmsWISCONSIN522021
FestinaIOWA502025

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