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

House Sparrow In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGeneralists

House Sparrow in Boreal Hardwood Transition has collapsed: down 77% on the route-weighted index since 1968.

-77%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 →
94Routes 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 →

House Sparrow has collapsed in Boreal Hardwood Transition: down 77% on the route-weighted index since 1968.

Forecast

If the recent trend holds, House Sparrow in Boreal Hardwood Transition is projected to fall about 75% by 2029 — from 1.1 in 2024 to a central estimate of 0.27 (95% range 0.00–2.9). A 5-year backtest shows a typical error of ±53.4%, with 100% of held-out values landing inside the 95% band.

-75%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 →
0.27Projected 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 →
0.00–2.995% 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 →
±53.4%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, House Sparrow in Boreal Hardwood Transition is projected to fall about 75% by 2029 — from 1.1 in 2024 to a central estimate of 0.27 (95% range 0.00–2.9). A 5-year backtest shows a typical error of ±53.4%, 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 →
20250.660.003.3
20260.560.003.2
20270.460.003.1
20280.360.003.0
20290.270.002.9

Routes In Boreal Hardwood Transition

Routes recording House Sparrow 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 →
HermanMICHIGAN261997
Rib LakeWISCONSIN262024
Maple GroveMICHIGAN251985
Lake CityMICHIGAN232022
Wigwam BayMINNESOTA232023
Traverse CtyMICHIGAN181992
Cedar RunMICHIGAN141999
HerronMICHIGAN122013
BemidjiMINNESOTA121980
WausaukeeWISCONSIN112024
GreenbushMINNESOTA102024
Hubbard LakeMICHIGAN91996
BrainerdMINNESOTA92024
BootjackMICHIGAN82021
IshpemingMICHIGAN81984
OberlinMICHIGAN72015
NebishMINNESOTA72023
OntonagonMICHIGAN62004
Crystal FlsMICHIGAN51991
WilsonMICHIGAN52010
TahquamenonMICHIGAN51990
IronsMICHIGAN41989
Walloon LakeMICHIGAN42004
IrmaWISCONSIN42024
CunardMICHIGAN32021

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