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

Red-throated Loon In BCR 2

All regionsBCR 2Wetland birds

Red-throated Loon in BCR 2 has surged: up 315% on the route-weighted index since 1986.

+315%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 →
17Routes 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 →
37YearsYears 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 →

Red-throated Loon has surged in BCR 2: up 315% on the route-weighted index since 1986.

Forecast

If the recent trend holds, Red-throated Loon in BCR 2 is projected to rise about 88% by 2029 — from 2.0 in 2024 to a central estimate of 3.8 (95% range 0.54–7.0). A 5-year backtest shows a typical error of ±137.8%, with 80% of held-out values landing inside the 95% band.

+88%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 →
3.8Projected 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 →
0.54–7.095% 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 →
±137.8%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, Red-throated Loon in BCR 2 is projected to rise about 88% by 2029 — from 2.0 in 2024 to a central estimate of 3.8 (95% range 0.54–7.0). A 5-year backtest shows a typical error of ±137.8%, with 80% 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 →
20253.50.316.8
20263.60.366.8
20273.70.426.9
20283.70.486.9
20293.80.547.0

Routes In BCR 2

Routes recording Red-throated Loon 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 →
KotzebueALASKA112024
NomeALASKA62023
Cape NomeALASKA32024
Salmon LakeALASKA32012
Goodnews BayALASKA32005
Kugarak (Short)ALASKA31987
ChiniakALASKA22006
Togiak RiverALASKA22005
Gweek RiverALASKA21998
Kanektok RivALASKA22005
DillinghamALASKA12000
Cold BayALASKA12024
King SalmonALASKA12024
Kodiak 2ALASKA12024
CouncilALASKA12024
Kotzebue (Short)ALASKA11994
Cold Bay (Short)ALASKA11992

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