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

Olive-sided Flycatcher Population Trend in New Hampshire

All statesAerial insectivores

Olive-sided Flycatcher in New Hampshire has collapsed: down 90% on the route-weighted index since 1968.

-90%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 →
21Routes 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 →
49YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Olive-sided 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 →

Olive-sided Flycatcher has collapsed in New Hampshire: down 90% on the route-weighted index since 1968.

Olive-sided Flycatcher Population Forecast in New Hampshire

If the recent trend holds, Olive-sided Flycatcher in New Hampshire is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–0.18). A 5-year backtest shows a typical error of ±200.7%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 →
0.00Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1895% 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 →
±200.7%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, Olive-sided Flycatcher in New Hampshire is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–0.18). A 5-year backtest shows a typical error of ±200.7%, with 100% of held-out values landing inside the 95% band.19662028
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 →
20240.000.000.18
20250.000.000.18
20260.000.000.18
20270.000.000.18
20280.000.000.18

Olive-sided Flycatcher Survey Routes in New Hampshire

Routes recording Olive-sided 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 →
Milan219811966
Brentwood119861968
Fitzwilliam119661966
Dover119701966
Hopkinton119871971
Epsom119711970
Concord119761967
Strafford119761976
Wilmot120011973
Mt Chocorua120211973
Marlow119831975
Lempster119851969
Crawford Not119701966
Jefferson Hl120161966
Franconia120081966
Stratford119831974
Dixvil Notch120171966
Clarksville120231967
Glen120221975
Jeffers Ntch120121995
Dixville Notch 2120192019

Olive-sided Flycatcher Population Trend in Other States

alaskaarizonacaliforniacoloradoidahomainemarylandmassachusettsmichiganminnesotamontananevadanew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniasouth-dakotautahvermontwashingtonwest-virginiawisconsinwyoming

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