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

Long-tailed Jaeger In BCR 2

All regionsBCR 2Generalists

Long-tailed Jaeger in BCR 2 has surged: up 202% on the route-weighted index since 1989.

+202%Since 1989TrendPercent 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 →
14Routes 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 →
34YearsYears 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 →

long arc increasecomputed 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 →

Long-tailed Jaeger has surged in BCR 2: up 202% on the route-weighted index since 1989.

Long-tailed Jaeger In BCR 2 Population Forecast

If the recent trend holds, Long-tailed Jaeger in BCR 2 is projected to rise about 72% by 2029 — from 1.9 in 2024 to a central estimate of 3.3 (95% range 0.00–7.1). A 5-year backtest shows a typical error of ±63.1%, with 100% of held-out values landing inside the 95% band.

+72%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 →
3.3Projected 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 →
0.00–7.195% 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 →
±63.1%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, Long-tailed Jaeger in BCR 2 is projected to rise about 72% by 2029 — from 1.9 in 2024 to a central estimate of 3.3 (95% range 0.00–7.1). A 5-year backtest shows a typical error of ±63.1%, 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 →
20253.30.007.1
20263.30.007.1
20273.30.007.1
20283.30.007.1
20293.30.007.1

Routes In BCR 2

Routes recording Long-tailed 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 →
NomeALASKA322023
Cape NomeALASKA92024
St. Mary'SALASKA62014
Kugarak (Short)ALASKA61987
TellerALASKA52024
Selawik (Short)ALASKA51987
CouncilALASKA42023
Gweek RiverALASKA31997
KotzebueALASKA32024
Kotzebue (Short)ALASKA31994
Goodnews BayALASKA22003
King SalmonALASKA12023
Salmon LakeALASKA12019
Cold Bay (Short)ALASKA11989

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