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

Great-tailed Grackle In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGeneralists

Great-tailed Grackle in Eastern Tallgrass Prairie has declined: down 49% on the route-weighted index since 1980.

-49%Since 1980TrendPercent 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 →
45Routes 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 →
46YearsYears 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 Great-tailed Grackle in Eastern Tallgrass Prairie. See the full index history below.

Great-tailed Grackle In Eastern Tallgrass Prairie Population Forecast

If the recent trend holds, Great-tailed Grackle in Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 0.12 (95% range 0.00–0.36). A 5-year backtest shows a typical error of ±176.6%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.12Projected 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 →
0.00–0.3695% 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 →
±176.6%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, Great-tailed Grackle in Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 0.12 (95% range 0.00–0.36). A 5-year backtest shows a typical error of ±176.6%, with 100% of held-out values landing inside the 95% band.19782029
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 →
20250.130.000.37
20260.130.000.37
20270.130.000.36
20280.120.000.36
20290.120.000.36

Routes In Eastern Tallgrass Prairie

Routes recording Great-tailed 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 →
WrefordKANSAS82023
GalesburgKANSAS72023
WalesIOWA52013
BarclayKANSAS52021
Le LoupKANSAS52012
MadisonMISSOURI52002
DoverKANSAS42022
Rock CreekKANSAS42002
CameronMISSOURI42007
PeoriaOKLAHOMA42015
LaplandKANSAS32016
MoreheadKANSAS32024
ReeceKANSAS32016
RockinghamMISSOURI31993
FrazierMISSOURI32018
New PointMISSOURI32019
KingsvilleMISSOURI31999
CollinsvilleOKLAHOMA32019
WainwrightOKLAHOMA32003
Terre HauteILLINOIS22012
NeolaIOWA22011
HudsonIOWA22022
Sioux CityIOWA22014
EllinorKANSAS22014
LincolnvilleKANSAS22016

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