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Species · Nevada · BBS 2025 Release · 1966–2024

MacGillivray's Warbler Population Trend in Nevada

All statesForest birds

MacGillivray's Warbler in Nevada has fallen sharply: down 50% on the route-weighted index since 1993.

-50%Since 1993TrendPercent 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 →
13Routes 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 →
33YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable MacGillivray's Warbler Trends in NevadaNotable 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 →

MacGillivray's Warbler has fallen sharply in Nevada: down 50% on the route-weighted index since 1993.

MacGillivray's Warbler Population Forecast in Nevada

If the recent trend holds, MacGillivray's Warbler in Nevada is projected to rise about 834% by 2029 — from 0.11 in 2024 to a central estimate of 1.00 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±2006.6%, with 0% of held-out values landing inside the 95% band.

+834%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 →
1.00Projected 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 →
0.00–2.295% 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 →
±2006.6%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, MacGillivray's Warbler in Nevada is projected to rise about 834% by 2029 — from 0.11 in 2024 to a central estimate of 1.00 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±2006.6%, with 0% of held-out values landing inside the 95% band.19882029
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 →
20250.940.002.2
20260.960.002.2
20270.970.002.2
20280.990.002.2
20291.000.002.2

MacGillivray's Warbler Survey Routes in Nevada

Routes recording MacGillivray's Warbler in Nevada.
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 →
Austin3620182008
Ruby Valley920011999
Hawthorne720011997
Jarbidge620151997
Comins Lake620162005
Ruby Valley 2320182004
Humboldt Nf220191994
Humboldt Nf 2220242021
Toiyabe Nf220182013
Dinner Sta119931991
Fish Creek120012001
Gardnerville120032003
Willis120241988

MacGillivray's Warbler Population Trend in Other States

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