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Species · BCR 4 · BBS 2026 Release · 1966–2025

Alder Flycatcher In BCR 4

All regionsBCR 4Aerial insectivores

Alder Flycatcher in BCR 4 has declined: down 44% on the route-weighted index since 1976.

-44%Since 1976TrendPercent 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 →
68Routes 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 →
48YearsYears 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 →

No notable trend signals for Alder Flycatcher in BCR 4. See the full index history below.

Alder Flycatcher In BCR 4 Population Forecast

If the recent trend holds, Alder Flycatcher in BCR 4 is projected to stay roughly flat through 2030, near 25 (95% range 7.8–42). A 5-year backtest shows a typical error of ±20.5%, with 100% of held-out values landing inside the 95% band.

-4%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 →
25Projected 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 →
7.8–4295% 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 →
±20.5%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, Alder Flycatcher in BCR 4 is projected to stay roughly flat through 2030, near 25 (95% range 7.8–42). A 5-year backtest shows a typical error of ±20.5%, with 100% of held-out values landing inside the 95% band.19682030
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 →
2026258.543
2027258.342
2028258.142
2029257.942
2030257.842

Routes In BCR 4

Routes recording Alder Flycatcher 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 →
Burma RoadALASKA1332025
Mud RiverALASKA1012024
Hather CreekALASKA952024
CottonwoodALASKA931990
PetersvilleALASKA902025
Kanuti LakeALASKA642024
WasillaALASKA611983
RubyALASKA592025
Hatcher PassALASKA542025
WillowALASKA522025
Moose CreekALASKA452022
CohoeALASKA442023
Ft. RichrdsnALASKA442023
Lake LouiseALASKA422025
CircleALASKA412025
HomerALASKA411982
ChistochinaALASKA402025
Kanuti CanynALASKA382024
McgrathALASKA382022
Goose BayALASKA371982
Seven LakesALASKA362025
EagleALASKA352025
Caribou Mtn.ALASKA352025
Manley Ht SpALASKA352022
Nicholai SlALASKA342025

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.