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

Black Swift Population Trend in Washington

All statesAerial insectivores

Black Swift in Washington has collapsed: down 92% on the route-weighted index since 1970.

-92%Since 1970TrendPercent 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 →
34Routes 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 →
52YearsYears 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 Swift Trends in WashingtonNotable 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 Swift has collapsed in Washington: down 92% on the route-weighted index since 1970.

Black Swift Population Forecast in Washington

If the recent trend holds, Black Swift in Washington is projected to fall about 100% by 2029 — from 0.10 in 2024 to a central estimate of 0.00 (95% range 0.00–2.7). A 5-year backtest shows a typical error of ±443.6%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–2.795% 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 →
±443.6%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, Black Swift in Washington is projected to fall about 100% by 2029 — from 0.10 in 2024 to a central estimate of 0.00 (95% range 0.00–2.7). A 5-year backtest shows a typical error of ±443.6%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.000.002.7
20260.000.002.7
20270.000.002.7
20280.000.002.7
20290.000.002.7

Black Swift Survey Routes in Washington

Routes recording Black Swift in Washington.
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 →
Carnation2420171988
Index2019711968
Warm Beach1119941970
Glacier1020221977
L. Wenatchee1020071994
Suiattle Riv920031994
Everett620231979
Cedar Falls619941994
Twisp520241972
Carlton520191993
Northport519991999
Issaquah419841979
Mt Rainier420001992
Rimrock319871987
Curlew319921992
Mazama320011993
Ozette219851972
Cascade Riv220031990
Keller219681968
Cougar219911991
Camas220082008
Ronald220171973
Packwood220181975
Hurricane Rg220102010
Mukilteo220162016

Black Swift Population Trend in Other States

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