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

Henslow's Sparrow In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionGrassland birds

Henslow's Sparrow in Prairie Hardwood Transition has collapsed: down 94% on the route-weighted index since 1968.

-94%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 →
97Routes 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 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 →

Henslow's Sparrow has collapsed in Prairie Hardwood Transition: down 94% on the route-weighted index since 1968.

Henslow's Sparrow In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Henslow's Sparrow in Prairie Hardwood Transition is projected to fall about 100% by 2030 — from 0.07 in 2025 to a central estimate of 0.00 (95% range 0.00–0.24). A 5-year backtest shows a typical error of ±345.1%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.2495% 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 →
±345.1%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 Prairie Hardwood Transition is projected to fall about 100% by 2030 — from 0.07 in 2025 to a central estimate of 0.00 (95% range 0.00–0.24). A 5-year backtest shows a typical error of ±345.1%, 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 →
20260.000.000.24
20270.000.000.24
20280.000.000.24
20290.000.000.24
20300.000.000.24

Routes In Prairie Hardwood Transition

Routes recording Henslow's Sparrow 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 →
TrempealeauWISCONSIN181984
HoltMICHIGAN91972
JuniataMICHIGAN71979
PackertownINDIANA41970
N FreedomWISCONSIN42025
HighlandWISCONSIN42012
DeckervilleMICHIGAN32001
Money CreekMINNESOTA32003
GilmantonWISCONSIN32019
Buena VistaWISCONSIN32022
LawrenceMICHIGAN21979
BravoMICHIGAN21985
GalesburgMICHIGAN22011
New BuffaloMICHIGAN22013
CaledoniaMINNESOTA22007
New LondonMINNESOTA22006
GlenwoodMINNESOTA22014
Sherburne NrMINNESOTA22013
UnityWISCONSIN21976
ClintonvilleWISCONSIN21983
PardeevilleWISCONSIN22005
Fall RiverWISCONSIN22018
Mount HorebWISCONSIN21982
HebronWISCONSIN21986
StetsonvilleWISCONSIN21994

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