BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Purple Martin In Great Basin

All regionsGreat BasinAerial insectivores

Purple Martin in Great Basin has declined: down 45% on the route-weighted index since 1982.

-45%Since 1982TrendPercent 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 →
12Routes 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 →
20YearsYears 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 →

No notable trend signals for Purple Martin in Great Basin. See the full index history below.

Forecast

If the recent trend holds, Purple Martin in Great Basin is projected to stay roughly flat through 2027, near 0.02 (95% range 0.00–0.05). A 5-year backtest shows a typical error of ±55.3%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0595% 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 →
±55.3%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, Purple Martin in Great Basin is projected to stay roughly flat through 2027, near 0.02 (95% range 0.00–0.05). A 5-year backtest shows a typical error of ±55.3%, with 100% of held-out values landing inside the 95% band.19742027
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 →
20230.020.000.05
20240.020.000.05
20250.020.000.05
20260.020.000.05
20270.020.000.05

Routes In Great Basin

Routes recording Purple Martin 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 →
PromontoryUTAH51974
NubieberCALIFORNIA42017
Iron GateCALIFORNIA32019
Badger CreekOREGON22022
Clear Lk ResCALIFORNIA11987
BartleCALIFORNIA12008
TionestaCALIFORNIA12016
Dell SpringOREGON11976
Modoc PointOREGON11982
Mt HoodOREGON12022
Hardware RanchUTAH12015
SnowdenWASHINGTON11982

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