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

Herring Gull In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionWetland birds

Herring Gull in Prairie Hardwood Transition has surged: up 12× on the route-weighted index since 1968.

12×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 →
30Routes 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 increasecomputed 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 →

Herring Gull has surged in Prairie Hardwood Transition: up 12× on the route-weighted index since 1968.

Herring Gull In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Herring Gull in Prairie Hardwood Transition is projected to rise about 12× by 2030 — from 0.09 in 2025 to a central estimate of 1.0 (95% range 0.00–2.9). A 5-year backtest shows a typical error of ±368%, with 100% of held-out values landing inside the 95% band.

12×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 →
1.0Projected 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 →
0.00–2.995% 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 →
±368%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 Prairie Hardwood Transition is projected to rise about 12× by 2030 — from 0.09 in 2025 to a central estimate of 1.0 (95% range 0.00–2.9). A 5-year backtest shows a typical error of ±368%, 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 →
20261.00.002.9
20271.00.002.9
20281.00.002.9
20291.00.002.9
20301.00.002.9

Routes In Prairie Hardwood Transition

Routes recording Herring Gull 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 →
ManitowocWISCONSIN1842024
AdairMICHIGAN331987
BismarkOHIO221995
St CharlesMICHIGAN191992
Indiana DuneINDIANA172022
LimestoneOHIO122019
GraytownOHIO91984
VickeryOHIO52025
RichmondMICHIGAN42014
ManawaWISCONSIN41988
Big Blue LkMICHIGAN22025
HamtramckMICHIGAN21984
DeckervilleMICHIGAN22016
EvergreenMINNESOTA21984
N BaltimoreOHIO21985
CochraneWISCONSIN22005
ElderonWISCONSIN21982
Pt WashingtnWISCONSIN22017
CoopersvilleMICHIGAN12012
HudsonWISCONSIN11981
DresserWISCONSIN11975
Wis RapidsWISCONSIN11994
Oconto FallsWISCONSIN11991
OmroWISCONSIN12001
CascoWISCONSIN12025

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