BirdAnalyst
Species · BCR 9 · BBS 2026 Release · 1966–2025

Wrentit In Great Basin

All regionsGreat BasinForest birds

Wrentit in Great Basin has fallen sharply: down 57% on the route-weighted index since 1973.

-57%Since 1973TrendPercent 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 →
6Routes 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 →
36YearsYears 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 →

Wrentit has fallen sharply in Great Basin: down 57% on the route-weighted index since 1973.

Wrentit In Great Basin Population Forecast

If the recent trend holds, Wrentit in Great Basin is projected to stay roughly flat through 2030, near 0.02 (95% range 0.00–0.06). A 5-year backtest shows a typical error of ±46.1%, 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 →
0.02Projected 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 →
0.00–0.0695% 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 →
±46.1%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, Wrentit in Great Basin is projected to stay roughly flat through 2030, near 0.02 (95% range 0.00–0.06). A 5-year backtest shows a typical error of ±46.1%, with 100% of held-out values landing inside the 95% band.19712030
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 →
20260.020.000.06
20270.020.000.06
20280.020.000.06
20290.020.000.06
20300.020.000.06

Routes In Great Basin

Routes recording Wrentit in Great Basin.
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 →
BartleCALIFORNIA52021
Barnes ValOREGON51972
Iron GateCALIFORNIA22019
NubieberCALIFORNIA12017
LikelyCALIFORNIA12025
Fall River MillsCALIFORNIA12011

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