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

Alder Flycatcher In BCR 4

All regionsBCR 4Aerial insectivores

Alder Flycatcher in BCR 4 has declined: down 36% on the route-weighted index since 1976.

-36%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 →
47YearsYears 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.

Forecast

If the recent trend holds, Alder Flycatcher in BCR 4 is projected to fall about 22% by 2029 — from 32 in 2024 to a central estimate of 25 (95% range 7.8–42). A 5-year backtest shows a typical error of ±23.2%, with 100% of held-out values landing inside the 95% band.

-22%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 →
25Projected 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 →
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 →
±23.2%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 fall about 22% by 2029 — from 32 in 2024 to a central estimate of 25 (95% range 7.8–42). A 5-year backtest shows a typical error of ±23.2%, with 100% of held-out values landing inside the 95% band.19682029
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 →
2025268.543
2026268.343
2027258.243
2028258.043
2029257.842

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 RoadALASKA1292024
Mud RiverALASKA1012024
Hather CreekALASKA952024
CottonwoodALASKA931990
PetersvilleALASKA892024
CircleALASKA762024
WillowALASKA692024
Kanuti LakeALASKA642024
WasillaALASKA611983
RubyALASKA512024
Nicholai SlALASKA472024
Moose CreekALASKA452022
Hatcher PassALASKA442024
CohoeALASKA442023
Ft. RichrdsnALASKA442023
HomerALASKA411982
L SalchaALASKA412023
EagleALASKA402024
NorthwayALASKA382023
Kanuti CanynALASKA382024
McgrathALASKA382022
Goose BayALASKA371982
ChickenALASKA362024
Manley Ht SpALASKA352022
Tower BluffsALASKA332023

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