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

Herring Gull In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionWetland birds

Herring Gull in Boreal Hardwood Transition has collapsed: down 96% on the route-weighted index since 1968.

-96%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 →
54Routes 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 →

long arc declinecomputed 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 collapsed in Boreal Hardwood Transition: down 96% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Herring Gull in Boreal Hardwood Transition is projected to fall about 100% by 2029 — from 0.47 in 2024 to a central estimate of 0.00 (95% range 0.00–7.9). A 5-year backtest shows a typical error of ±605.4%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–7.995% 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 →
±605.4%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 Boreal Hardwood Transition is projected to fall about 100% by 2029 — from 0.47 in 2024 to a central estimate of 0.00 (95% range 0.00–7.9). A 5-year backtest shows a typical error of ±605.4%, 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 →
20250.000.007.9
20260.000.007.9
20270.000.007.9
20280.000.007.9
20290.000.007.9

Routes In Boreal Hardwood Transition

Routes recording Herring Gull 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 →
CathroMICHIGAN1002016
Lake CityMICHIGAN261998
Washington IWISCONSIN192024
Hiawatha NfMICHIGAN142022
BayfieldWISCONSIN131999
PickfordMICHIGAN102024
TahquamenonMICHIGAN62010
Skegemog PtMICHIGAN62019
NebishMINNESOTA51986
HermanMICHIGAN42013
WilsonMICHIGAN42005
Iron RiverWISCONSIN42024
CreightonMICHIGAN31989
IsabellaMICHIGAN32004
OntonagonMICHIGAN22017
BerglandMICHIGAN22015
BootjackMICHIGAN22016
CunardMICHIGAN22004
GilchristMICHIGAN22018
RacoMICHIGAN21994
Hubbard LakeMICHIGAN21996
Walloon Lake 2MICHIGAN22010
HerronMICHIGAN22013
Island LakeMINNESOTA22016
Little ForkMINNESOTA21995

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