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

Herring Gull In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieWetland birds

Herring Gull in Eastern Tallgrass Prairie has held roughly steady: down 7% on the route-weighted index since 1986.

-7%Since 1986TrendPercent 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 →
11Routes 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 →
30YearsYears 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 Herring Gull in Eastern Tallgrass Prairie. See the full index history below.

Forecast

If the recent trend holds, Herring Gull in Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.17). A 5-year backtest shows a typical error of ±213.5%, 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 →
0.01Projected 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 →
0.00–0.1795% 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 →
±213.5%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, Herring Gull in Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.17). A 5-year backtest shows a typical error of ±213.5%, with 100% of held-out values landing inside the 95% band.19802029
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 →
20250.020.000.18
20260.020.000.18
20270.010.000.18
20280.010.000.17
20290.010.000.17

Routes In Eastern Tallgrass Prairie

Routes recording Herring Gull 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 →
ItascaILLINOIS32022
BotkinsOHIO32019
SherburnvillILLINOIS22018
GaryINDIANA21999
WayneILLINOIS12013
New LenoxILLINOIS11988
PortageINDIANA12004
Portage 2INDIANA12011
Kankakee SandsINDIANA12004
NorwalkOHIO12019
RaymondWISCONSIN12024

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