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

Henslow's Sparrow In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGrassland birds

Henslow's Sparrow in Boreal Hardwood Transition has declined: down 39% on the route-weighted index since 1971.

-39%Since 1971TrendPercent 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 →
22Routes 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 →
34YearsYears 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 Henslow's Sparrow in Boreal Hardwood Transition. See the full index history below.

Forecast

If the recent trend holds, Henslow's Sparrow in Boreal Hardwood Transition is projected to stay roughly flat through 2020, near 0.00 (95% range 0.00–0.06). A 5-year backtest shows a typical error of ±45.7%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2020TrendPercent 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 2020 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0695% 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 →
±45.7%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, Henslow's Sparrow in Boreal Hardwood Transition is projected to stay roughly flat through 2020, near 0.00 (95% range 0.00–0.06). A 5-year backtest shows a typical error of ±45.7%, with 100% of held-out values landing inside the 95% band.19682020
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 →
20160.010.000.07
20170.010.000.06
20180.010.000.06
20190.010.000.06
20200.000.000.06

Routes In Boreal Hardwood Transition

Routes recording Henslow's 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 →
MinongWISCONSIN22009
Rib LakeWISCONSIN21991
Ned LakeMICHIGAN12008
Maple GroveMICHIGAN11985
WilsonMICHIGAN11984
CunardMICHIGAN12004
Pleasant ValMICHIGAN11991
Lake CityMICHIGAN12008
SkeelsMICHIGAN12000
Sand LakeMICHIGAN11996
Hubbard LakeMICHIGAN11975
MayfieldMICHIGAN12007
BrainerdMINNESOTA12003
CouderayWISCONSIN11973
ExelandWISCONSIN11983
GilmanWISCONSIN11982
PhillipsWISCONSIN12008
IrmaWISCONSIN11984
Eagle RiverWISCONSIN11987
HollisterWISCONSIN11976
Washington IWISCONSIN12002
Amnicon FallsWISCONSIN12015

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