BirdAnalyst
Species · BCR 16 · BBS 2025 Release · 1966–2024

Lucy's Warbler In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauArid-land birds

Lucy's Warbler in Southern Rockies / Colorado Plateau has surged: up 664% on the route-weighted index since 1994.

+664%Since 1994TrendPercent 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 →
27YearsYears 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 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 →

Lucy's Warbler has surged in Southern Rockies / Colorado Plateau: up 664% on the route-weighted index since 1994.

Lucy's Warbler In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Lucy's Warbler in Southern Rockies / Colorado Plateau is projected to rise about 85% by 2029 — from 0.08 in 2024 to a central estimate of 0.14 (95% range 0.08–0.21). A 5-year backtest shows a typical error of ±33.9%, with 80% of held-out values landing inside the 95% band.

+85%Change by 2029TrendPercent 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 →
0.14Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.08–0.2195% 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 →
±33.9%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, Lucy's Warbler in Southern Rockies / Colorado Plateau is projected to rise about 85% by 2029 — from 0.08 in 2024 to a central estimate of 0.14 (95% range 0.08–0.21). A 5-year backtest shows a typical error of ±33.9%, with 80% of held-out values landing inside the 95% band.19922029
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 →
20250.130.060.19
20260.130.070.20
20270.140.070.20
20280.140.070.20
20290.140.080.21

Routes In Southern Rockies / Colorado Plateau

Routes recording Lucy's Warbler in Southern Rockies / Colorado Plateau.
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 →
Peach SpringARIZONA32024
AnethUTAH22024
Moquith MtnUTAH22003
HatchUTAH22024
MoabUTAH22024
ShivwitzUTAH12024

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