BirdAnalyst
Species · New Hampshire · BBS 2025 Release · 1966–2024

Yellow-bellied Flycatcher Population Trend in New Hampshire

All statesAerial insectivores

Yellow-bellied Flycatcher in New Hampshire has collapsed: down 82% on the route-weighted index since 1968.

-82%Since 1968TrendPercent 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 →
13Routes 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 →
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 Yellow-bellied Flycatcher Trends in New HampshireNotable 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 New Hampshire: down 82% on the route-weighted index since 1968.

Yellow-bellied Flycatcher Population Forecast in New Hampshire

If the recent trend holds, Yellow-bellied Flycatcher in New Hampshire is projected to fall about 91% by 2029 — from 0.09 in 2024 to a central estimate of 0.01 (95% range 0.00–0.25). A 5-year backtest shows a typical error of ±41.6%, with 100% of held-out values landing inside the 95% band.

-91%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 →
0.01Projected 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 →
0.00–0.2595% 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 →
±41.6%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 New Hampshire is projected to fall about 91% by 2029 — from 0.09 in 2024 to a central estimate of 0.01 (95% range 0.00–0.25). A 5-year backtest shows a typical error of ±41.6%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.030.000.28
20260.020.000.27
20270.020.000.27
20280.010.000.26
20290.010.000.25

Yellow-bellied Flycatcher Survey Routes in New Hampshire

Routes recording Yellow-bellied Flycatcher in New Hampshire.
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 →
Stratford219721966
Dixville Notch 2220242024
Brentwood119811981
Hopkinton119681968
Strafford120231968
Wilmot119781977
Mt Chocorua120211968
Jefferson Hl120231971
Franconia120141966
Milan120191966
Dixvil Notch120131966
Clarksville120161966
Jeffers Ntch120141993

Yellow-bellied Flycatcher Population Trend in Other States

alaskamainemassachusettsmichiganminnesotanew-yorkpennsylvaniavermontwisconsin

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