BirdAnalyst
Species · BCR 34 · BBS 2025 Release · 1966–2024

Olive Warbler In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Olive Warbler in Sierra Madre Occidental has surged: up 301% on the route-weighted index since 1979.

+301%Since 1979TrendPercent 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 →
16Routes 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 →
42YearsYears 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 →

Olive Warbler has surged in Sierra Madre Occidental: up 300% on the route-weighted index since 1979.

Forecast

If the recent trend holds, Olive Warbler in Sierra Madre Occidental is projected to rise about 314% by 2029 — from 0.22 in 2024 to a central estimate of 0.92 (95% range 0.40–1.4). A 5-year backtest shows a typical error of ±68.8%, with 80% of held-out values landing inside the 95% band.

+314%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 →
0.92Projected 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 →
0.40–1.495% 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 →
±68.8%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, Olive Warbler in Sierra Madre Occidental is projected to rise about 314% by 2029 — from 0.22 in 2024 to a central estimate of 0.92 (95% range 0.40–1.4). A 5-year backtest shows a typical error of ±68.8%, with 80% of held-out values landing inside the 95% band.19772029
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 →
20250.860.341.4
20260.870.361.4
20270.890.371.4
20280.900.391.4
20290.920.401.4

Routes In Sierra Madre Occidental

Routes recording Olive Warbler in Sierra Madre Occidental.
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 →
Mt. GrahamARIZONA142023
SprucedaleARIZONA62023
ReserveNEW-MEXICO62023
PrescottARIZONA32018
Forest LakesARIZONA32021
WilliamsARIZONA22001
PinetopARIZONA22022
AlpineARIZONA22022
Happy JackARIZONA22024
Carr MtnARIZONA22018
PortalARIZONA22024
Vicks PeakNEW-MEXICO22004
Aztec PeakARIZONA11977
Tonto Vill.ARIZONA12017
RuckerARIZONA12004
Emory PassNEW-MEXICO12016

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