BirdAnalyst
Species · Nevada · BBS 2025 Release · 1966–2024

Black-tailed Gnatcatcher Population Trend in Nevada

All statesArid-land birds

Black-tailed Gnatcatcher in Nevada has fallen sharply: down 74% on the route-weighted index since 1973.

-74%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 →
8Routes 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 Black-tailed Gnatcatcher 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 →

Black-tailed Gnatcatcher has fallen sharply in Nevada: down 74% on the route-weighted index since 1973.

Black-tailed Gnatcatcher Population Forecast in Nevada

If the recent trend holds, Black-tailed Gnatcatcher in Nevada is projected to rise about 83% by 2029 — from 0.07 in 2024 to a central estimate of 0.13 (95% range 0.00–0.59). A 5-year backtest shows a typical error of ±146.1%, with 100% of held-out values landing inside the 95% band.

+83%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 →
0.13Projected 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 →
0.00–0.5995% 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 →
±146.1%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, Black-tailed Gnatcatcher in Nevada is projected to rise about 83% by 2029 — from 0.07 in 2024 to a central estimate of 0.13 (95% range 0.00–0.59). A 5-year backtest shows a typical error of ±146.1%, with 100% of held-out values landing inside the 95% band.19702029
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 →
20250.150.000.61
20260.150.000.61
20270.140.000.60
20280.140.000.59
20290.130.000.59

Black-tailed Gnatcatcher Survey Routes in Nevada

Routes recording Black-tailed Gnatcatcher 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 →
Desert Nwr420112010
Ash Meadows420062006
Hiko419701970
Jean Lake319931973
Beatty220172009
Nelson120241995
Alamo119731972
Val Of Fire120241986

Black-tailed Gnatcatcher Population Trend in Other States

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