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Species · BCR 2 · BBS 2025 Release · 1966–2024

Parasitic Jaeger In BCR 2

All regionsBCR 2Generalists

Parasitic Jaeger in BCR 2 has declined: down 43% on the route-weighted index since 1991.

-43%Since 1991TrendPercent 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 RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
32YearsYears 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 Parasitic Jaeger in BCR 2. See the full index history below.

Parasitic Jaeger In BCR 2 Population Forecast

If the recent trend holds, Parasitic Jaeger in BCR 2 is projected to rise about 81% by 2029 — from 0.22 in 2024 to a central estimate of 0.40 (95% range 0.00–0.93). A 5-year backtest shows a typical error of ±138.5%, with 100% of held-out values landing inside the 95% band.

+81%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 →
0.40Projected 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 →
0.00–0.9395% 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 →
±138.5%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, Parasitic Jaeger in BCR 2 is projected to rise about 81% by 2029 — from 0.22 in 2024 to a central estimate of 0.40 (95% range 0.00–0.93). A 5-year backtest shows a typical error of ±138.5%, with 100% of held-out values landing inside the 95% band.19862029
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 →
20250.400.000.93
20260.400.000.93
20270.400.000.93
20280.400.000.93
20290.400.000.93

Routes In BCR 2

Routes recording Parasitic Jaeger in BCR 2.
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 →
King SalmonALASKA32023
TupuknukALASKA31995
Kotzebue (Short)ALASKA31986
Cold BayALASKA22024
TellerALASKA22017
KotzebueALASKA22019
ChiniakALASKA11989
Cape NomeALASKA12018
CouncilALASKA12009
NomeALASKA12012
Salmon LakeALASKA11998
St. Mary'SALASKA12012
Cold Bay (Short)ALASKA11992

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