BirdAnalyst
Species · Maine · BBS 2025 Release · 1966–2024

Yellow-bellied Flycatcher Population Trend in Maine

All statesAerial insectivores

Yellow-bellied Flycatcher in Maine has collapsed: down 89% on the route-weighted index since 1972.

-89%Since 1972TrendPercent 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 →
57Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
53YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow-bellied Flycatcher Trends in MaineNotable 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 →

Yellow-bellied Flycatcher has collapsed in Maine: down 89% on the route-weighted index since 1972.

Yellow-bellied Flycatcher Population Forecast in Maine

If the recent trend holds, Yellow-bellied Flycatcher in Maine is projected to stay roughly flat through 2029, near 0.19 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±42.6%, with 100% of held-out values landing inside the 95% band.

-8%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 →
0.19Projected 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 →
0.00–2.295% 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 →
±42.6%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, Yellow-bellied Flycatcher in Maine is projected to stay roughly flat through 2029, near 0.19 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±42.6%, 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 →
20250.240.002.3
20260.230.002.3
20270.220.002.2
20280.210.002.2
20290.190.002.2

Yellow-bellied Flycatcher Survey Routes in Maine

Routes recording Yellow-bellied Flycatcher in Maine.
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 →
Pillsbury Pd4619681968
Big Twenty 2520092009
Yankeetuladi520091995
Wilson Mills420241983
Nesowadnehun320212016
South Arm319881983
Northfield319811977
Horse Mtn319971986
Weeks Brook320161995
Clayton Lake 2320112011
Heron Lake320031983
Northfield 2220222014
Andover220212010
Moose River219901983
Carrying Pl220231993
Greenville220051972
Forest Sta220001974
Clayton Lake220081977
Big Twenty220081995
Telos219951995
Baker Lake220091995
Stacyville220232021
Westbrook119941986
Newcastle119991972
Bethel120192007

Yellow-bellied Flycatcher Population Trend in Other States

alaskamassachusettsmichiganminnesotanew-hampshirenew-yorkpennsylvaniavermontwisconsin

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