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

Tundra Swan In BCR 2

All regionsBCR 2Waterfowl

Tundra Swan in BCR 2 has surged: up 190% on the route-weighted index since 1986.

+190%Since 1986TrendPercent 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 →
18Routes 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 →
39YearsYears 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 →

Tundra Swan has surged in BCR 2: up 190% on the route-weighted index since 1986.

Tundra Swan In BCR 2 Population Forecast

If the recent trend holds, Tundra Swan in BCR 2 is projected to rise about 59% by 2029 — from 6.7 in 2024 to a central estimate of 11 (95% range 0.00–31). A 5-year backtest shows a typical error of ±720.6%, with 100% of held-out values landing inside the 95% band.

+59%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 →
11Projected 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 →
0.00–3195% 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 →
±720.6%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, Tundra Swan in BCR 2 is projected to rise about 59% by 2029 — from 6.7 in 2024 to a central estimate of 11 (95% range 0.00–31). A 5-year backtest shows a typical error of ±720.6%, with 100% of held-out values landing inside the 95% band.19842029
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 →
2025100.0030
2026100.0030
2027100.0030
2028100.0030
2029110.0031

Routes In BCR 2

Routes recording Tundra Swan 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 SalmonALASKA212024
Cape NomeALASKA192024
Cold BayALASKA122024
Cold Bay (Short)ALASKA91992
NomeALASKA72022
Kugarak (Short)ALASKA51987
TellerALASKA32024
KotzebueALASKA32024
Selawik (Short)ALASKA31987
CouncilALASKA22024
Salmon LakeALASKA22019
St. Mary'SALASKA22000
Kanektok RivALASKA21999
Goodnews BayALASKA22004
Katmai N.P.ALASKA12022
DillinghamALASKA12014
Togiak RiverALASKA12003
Gweek RiverALASKA12002

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