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Species · BCR 2 · BBS 2026 Release · 1966–2025

Tundra Swan In BCR 2

All regionsBCR 2Waterfowl

Tundra Swan in BCR 2 has surged: up 143% on the route-weighted index since 1986.

+143%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 →
40YearsYears 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 143% 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 352% by 2030 — from 2.2 in 2025 to a central estimate of 9.8 (95% range 0.00–30). A 5-year backtest shows a typical error of ±690.9%, with 100% of held-out values landing inside the 95% band.

+352%Change by 2030TrendPercent 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 →
9.8Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–3095% 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 →
±690.9%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 352% by 2030 — from 2.2 in 2025 to a central estimate of 9.8 (95% range 0.00–30). A 5-year backtest shows a typical error of ±690.9%, with 100% of held-out values landing inside the 95% band.19842030
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 →
20269.40.0029
20279.50.0029
20289.60.0029
20299.70.0030
20309.80.0030

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 →
Cape NomeALASKA192024
Cold Bay (Short)ALASKA91992
NomeALASKA72022
Cold BayALASKA52025
King SalmonALASKA52025
Kugarak (Short)ALASKA51987
TellerALASKA32024
KotzebueALASKA32025
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 2026-08-14.