BirdAnalyst
Species · BCR 12 · BBS 2026 Release · 1966–2025

Common Grackle In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGeneralists

Common Grackle in Boreal Hardwood Transition has edged down: down 17% on the route-weighted index since 1968.

-17%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 →
126Routes 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 →

No notable trend signals for Common Grackle in Boreal Hardwood Transition. See the full index history below.

Common Grackle In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Common Grackle in Boreal Hardwood Transition is projected to stay roughly flat through 2030, near 4.6 (95% range 0.91–8.3). A 5-year backtest shows a typical error of ±15.3%, with 100% of held-out values landing inside the 95% band.

-10%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 →
4.6Projected 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 →
0.91–8.395% 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 →
±15.3%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 Boreal Hardwood Transition is projected to stay roughly flat through 2030, near 4.6 (95% range 0.91–8.3). A 5-year backtest shows a typical error of ±15.3%, 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 →
20264.91.28.6
20274.81.18.5
20284.71.18.4
20294.70.998.3
20304.60.918.3

Routes In Boreal Hardwood Transition

Routes recording Common Grackle in Boreal 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 →
MayfieldMICHIGAN572025
Walloon Lake 2MICHIGAN512024
SkeelsMICHIGAN472015
Traverse CtyMICHIGAN361992
MareniscoMICHIGAN302019
Sand LakeMICHIGAN252025
PickfordMICHIGAN212025
ShanagoldenWISCONSIN212024
FredericMICHIGAN202003
RiggsvilleMICHIGAN192019
Crystal FlsMICHIGAN182025
IshpemingMICHIGAN172025
Cedar RunMICHIGAN171999
Pine RiverMINNESOTA162025
Rib LakeWISCONSIN162025
Pleasant Valley 2MICHIGAN152025
CouderayWISCONSIN152025
Union TwpWISCONSIN142024
Ned LakeMICHIGAN132025
IronsMICHIGAN131989
Little ForkMINNESOTA132024
Walloon LakeMICHIGAN122004
Brush CreekMICHIGAN112016
CathroMICHIGAN112016
CavourWISCONSIN112025

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