BirdAnalyst
Species · BCR 28 · BBS 2026 Release · 1966–2025

Alder Flycatcher In Appalachian Mountains

All regionsAppalachian MountainsAerial insectivores

Alder Flycatcher in Appalachian Mountains has surged: up 550% on the route-weighted index since 1970.

+550%Since 1970TrendPercent 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 →
134Routes 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 →
57YearsYears 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 →

Alder Flycatcher has surged in Appalachian Mountains: up 550% on the route-weighted index since 1970.

Alder Flycatcher In Appalachian Mountains Population Forecast

If the recent trend holds, Alder Flycatcher in Appalachian Mountains is projected to stay roughly flat through 2030, near 0.48 (95% range 0.36–0.61). A 5-year backtest shows a typical error of ±27.7%, with 80% of held-out values landing inside the 95% band.

+9%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 →
0.48Projected 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 →
0.36–0.6195% 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 →
±27.7%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, Alder Flycatcher in Appalachian Mountains is projected to stay roughly flat through 2030, near 0.48 (95% range 0.36–0.61). A 5-year backtest shows a typical error of ±27.7%, with 80% of held-out values landing inside the 95% band.19672030
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 →
20260.460.330.58
20270.470.340.59
20280.470.340.60
20290.480.350.60
20300.480.360.61

Routes In Appalachian Mountains

Routes recording Alder Flycatcher in Appalachian Mountains.
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 →
MeridaleNEW-YORK112025
DrydenNEW-YORK112025
S Berne 2NEW-YORK102025
Platte CoveNEW-YORK92018
OneontaNEW-YORK82025
Phillips CrNEW-YORK82025
Little MarshPENNSYLVANIA82023
EllentonPENNSYLVANIA72025
McdonoughNEW-YORK62017
MilfordNEW-YORK62023
EldredPENNSYLVANIA62015
RoulettePENNSYLVANIA52021
AustinvillePENNSYLVANIA52025
MedusaNEW-YORK42023
S BerneNEW-YORK42013
RasselasPENNSYLVANIA42022
LoguePENNSYLVANIA42025
StarlightPENNSYLVANIA41992
GreentownPENNSYLVANIA42024
GladyWEST-VIRGINIA42025
Vestal CtrNEW-YORK32018
CattaraugusNEW-YORK32019
East JavaNEW-YORK32025
Swain 2NEW-YORK32025
BusickNORTH-CAROLINA31994

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