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Species · Oklahoma · BBS 2025 Release · 1966–2024

Henslow's Sparrow Population Trend in Oklahoma

All statesGrassland birds

Henslow's Sparrow in Oklahoma has fallen sharply: down 65% on the route-weighted index since 1995.

-65%Since 1995TrendPercent 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 →
4Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
28YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Henslow's Sparrow Trends in OklahomaNotable 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 fallen sharply in Oklahoma: down 65% on the route-weighted index since 1995.

Henslow's Sparrow Population Forecast in Oklahoma

If the recent trend holds, Henslow's Sparrow in Oklahoma is projected to stay roughly flat through 2027, near 0.02 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±79.3%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 →
0.02Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.2795% 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 →
±79.3%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 Oklahoma is projected to stay roughly flat through 2027, near 0.02 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±79.3%, with 100% of held-out values landing inside the 95% band.19932027
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 →
20230.050.000.30
20240.040.000.29
20250.040.000.28
20260.030.000.28
20270.020.000.27

Henslow's Sparrow Survey Routes in Oklahoma

Routes recording Henslow's Sparrow in Oklahoma.
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 →
Bartlesville220192006
Foraker120221993
Skiatook120102010
Welch120071994

Henslow's Sparrow Population Trend in Other States

delawareillinoisindianaiowakansaskentuckymarylandmichiganminnesotamissourinebraskanew-yorknorth-carolinanorth-dakotaohiopennsylvaniasouth-dakotavermontvirginiawest-virginiawisconsin

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