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Species · BCR 12 · BBS 2025 Release · 1966–2024

Common Grackle In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGeneralists

Common Grackle in Boreal Hardwood Transition has edged down: down 19% on the route-weighted index since 1968.

-19%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 →
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 →

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 fall about 19% by 2029 — from 5.7 in 2024 to a central estimate of 4.7 (95% range 0.94–8.4). A 5-year backtest shows a typical error of ±20.9%, with 100% of held-out values landing inside the 95% band.

-19%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 →
4.7Projected 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 →
0.94–8.495% 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 →
±20.9%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 Boreal Hardwood Transition is projected to fall about 19% by 2029 — from 5.7 in 2024 to a central estimate of 4.7 (95% range 0.94–8.4). A 5-year backtest shows a typical error of ±20.9%, 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 →
20254.91.28.7
20264.91.28.6
20274.81.18.5
20284.71.08.4
20294.70.948.4

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 →
Brocky LakeMICHIGAN532024
Walloon Lake 2MICHIGAN512024
SkeelsMICHIGAN472015
Traverse CtyMICHIGAN361992
MareniscoMICHIGAN302019
MayfieldMICHIGAN252022
ShanagoldenWISCONSIN212024
FredericMICHIGAN202003
PickfordMICHIGAN192024
RiggsvilleMICHIGAN192019
Cedar RunMICHIGAN171999
Crystal FlsMICHIGAN162024
PhillipsWISCONSIN162024
Pleasant Valley 2MICHIGAN142024
Union TwpWISCONSIN142024
IronsMICHIGAN131989
Little ForkMINNESOTA132024
Bear LakeMICHIGAN122024
Skegemog PtMICHIGAN122024
Walloon LakeMICHIGAN122004
Brush CreekMICHIGAN112016
CathroMICHIGAN112016
NebishMINNESOTA112022
Rib LakeWISCONSIN112024
IrmaWISCONSIN112024

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