BirdAnalyst
Species · Kansas · BBS 2026 Release · 1966–2025

Vesper Sparrow Population Trend in Kansas

All statesGrassland birds

Vesper Sparrow in Kansas has fallen sharply: down 59% on the route-weighted index since 1975.

-59%Since 1975TrendPercent 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 →
15Routes 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 →
30YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Vesper Sparrow Trends in KansasNotable 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 →

Vesper Sparrow has fallen sharply in Kansas: down 59% on the route-weighted index since 1975.

Vesper Sparrow Population Forecast in Kansas

If the recent trend holds, Vesper Sparrow in Kansas is projected to stay roughly flat through 2030, near 0.10 (95% range 0.00–0.26). A 5-year backtest shows a typical error of ±166.1%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.10Projected 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 →
0.00–0.2695% 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 →
±166.1%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, Vesper Sparrow in Kansas is projected to stay roughly flat through 2030, near 0.10 (95% range 0.00–0.26). A 5-year backtest shows a typical error of ±166.1%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20260.100.000.26
20270.100.000.26
20280.100.000.26
20290.100.000.26
20300.100.000.26

Vesper Sparrow Survey Routes in Kansas

Routes recording Vesper Sparrow in Kansas.
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 →
Ulysses1620032003
Ruleton420101981
Seneca320222007
Minneapolis319761976
Melrose219791979
Coats219721972
Barclay219841984
Grantville220132008
Olsburg220092006
Galesburg119751975
Longton119791979
Ashland119831969
Dover120072007
Buckeye120102010
Severance120252000

Vesper Sparrow Population Trend in Other States

arizonacaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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