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

Olive-sided Flycatcher In BCR 4

All regionsBCR 4Aerial insectivores

Olive-sided Flycatcher in BCR 4 has risen sharply: up 50% on the route-weighted index since 1982.

+50%Since 1982TrendPercent 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 →
60Routes 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 →
44YearsYears 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 →

Olive-sided Flycatcher has risen sharply in BCR 4: up 50% on the route-weighted index since 1982.

Olive-sided Flycatcher In BCR 4 Population Forecast

If the recent trend holds, Olive-sided Flycatcher in BCR 4 is projected to rise about 15% by 2029 — from 2.3 in 2024 to a central estimate of 2.6 (95% range 1.1–4.1). A 5-year backtest shows a typical error of ±12.6%, with 100% of held-out values landing inside the 95% band.

+15%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 →
2.6Projected 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 →
1.1–4.195% 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 →
±12.6%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, Olive-sided Flycatcher in BCR 4 is projected to rise about 15% by 2029 — from 2.3 in 2024 to a central estimate of 2.6 (95% range 1.1–4.1). A 5-year backtest shows a typical error of ±12.6%, 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 →
20252.61.14.1
20262.61.14.1
20272.61.14.1
20282.61.14.1
20292.61.14.1

Routes In BCR 4

Routes recording Olive-sided 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 →
Kanuti LakeALASKA202024
Bear CreekALASKA91991
CircleALASKA82024
L SalchaALASKA82023
Seven LakesALASKA82023
ColdfootALASKA82021
ChistochinaALASKA72022
Swan Lake RdALASKA72023
NorthwayALASKA62023
Goose BayALASKA61982
KalifonskyALASKA62023
Unalakleet RiverALASKA62024
Nabesna RoadALASKA62021
Skilak LakeALASKA51985
TonsinaALASKA52021
Nicholai SlALASKA52024
Manley Ht SpALASKA52022
Anvik RiverALASKA52022
EagleALASKA42024
HomerALASKA41982
Burma RoadALASKA42024
Kanuti CanynALASKA42024
McgrathALASKA42022
Moose CreekALASKA42022
Galena (Short)ALASKA42024

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