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

Vesper Sparrow Population Trend in Oregon

All statesGrassland birds

Vesper Sparrow in Oregon has surged: up 88% on the route-weighted index since 1970.

+88%Since 1970TrendPercent 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 →
85Routes 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 →
57YearsYears 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 OregonNotable 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 increasecomputed 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 surged in Oregon: up 88% on the route-weighted index since 1970.

Vesper Sparrow Population Forecast in Oregon

If the recent trend holds, Vesper Sparrow in Oregon is projected to rise about 18% by 2030 — from 5.6 in 2025 to a central estimate of 6.6 (95% range 1.8–11). A 5-year backtest shows a typical error of ±15.3%, with 100% of held-out values landing inside the 95% band.

+18%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 →
6.6Projected 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 →
1.8–1195% 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 →
±15.3%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, Vesper Sparrow in Oregon is projected to rise about 18% by 2030 — from 5.6 in 2025 to a central estimate of 6.6 (95% range 1.8–11). A 5-year backtest shows a typical error of ±15.3%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20266.51.711
20276.51.811
20286.51.811
20296.51.811
20306.61.811

Vesper Sparrow Survey Routes in Oregon

Routes recording Vesper Sparrow in Oregon.
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 →
Zumwalt12720051995
Blitzen 26520251994
Battle Mtn6420251985
Buchanan5620251971
Flook Lake4820251994
Princeton4519851976
Malheur Res.3620232022
Catlow Rim3520251993
Clover Creek3420251972
Madras3320251997
Blitzen2619931971
Crane2520241993
Lone Rock2420241968
Green Mtn.2120251994
Bly2020011973
Lapham Res.2020251991
Barnes Val1919871972
Sheaville1920252012
Fish Lake1820251972
Barnhouse1620251998
Joseph1520251971
Eightmile1520251982
Bly 21520252007
Crooked Riv.1420251994
Blizzard Gap1220251984

Vesper Sparrow Population Trend in Other States

arizonacaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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