BirdAnalyst
Species · BCR 4 · BBS 2025 Release · 1966–2024

Barrow's Goldeneye In BCR 4

All regionsBCR 4Waterfowl

Barrow's Goldeneye in BCR 4 has fallen sharply: down 73% on the route-weighted index since 1987.

-73%Since 1987TrendPercent 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 →
20Routes 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 →
35YearsYears 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 declinecomputed 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 →

Barrow's Goldeneye has fallen sharply in BCR 4: down 73% on the route-weighted index since 1987.

Forecast

If the recent trend holds, Barrow's Goldeneye in BCR 4 is projected to fall about 96% by 2029 — from 0.11 in 2024 to a central estimate of 0.00 (95% range 0.00–0.33). A 5-year backtest shows a typical error of ±121.7%, with 60% of held-out values landing inside the 95% band.

-96%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 →
0.00Projected 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 →
0.00–0.3395% 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 →
±121.7%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, Barrow's Goldeneye in BCR 4 is projected to fall about 96% by 2029 — from 0.11 in 2024 to a central estimate of 0.00 (95% range 0.00–0.33). A 5-year backtest shows a typical error of ±121.7%, with 60% of held-out values landing inside the 95% band.19832029
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 →
20250.050.000.37
20260.040.000.36
20270.030.000.35
20280.020.000.34
20290.000.000.33

Routes In BCR 4

Routes recording Barrow's Goldeneye in BCR 4.
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 →
Mccarthy Rd2ALASKA92023
Pinoche Tral (Short)ALASKA41984
Kenny LakeALASKA22021
Lake LouiseALASKA22011
PetersvilleALASKA22003
Hather CreekALASKA22013
Nabesna RoadALASKA22015
SlanaALASKA12024
MaclarenALASKA12024
MonahanALASKA12013
CantwellALASKA12005
ToklatALASKA12018
SourdoughALASKA12024
TonsinaALASKA12014
SavageALASKA12008
Hatcher PassALASKA12010
Chena Hot Spring 2ALASKA11999
Seven LakesALASKA12023
Burma RoadALASKA12007
KuskulanaALASKA12024

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