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

Least Flycatcher Population Trend in New Jersey

All statesAerial insectivores

Least Flycatcher in New Jersey has fallen sharply: down 52% on the route-weighted index since 1969.

-52%Since 1969TrendPercent 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 →
14Routes 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 Least Flycatcher Trends in New JerseyNotable 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 →

Least Flycatcher has fallen sharply in New Jersey: down 52% on the route-weighted index since 1969.

Least Flycatcher Population Forecast in New Jersey

If the recent trend holds, Least Flycatcher in New Jersey is projected to stay roughly flat through 2029, near 0.10 (95% range 0.00–0.31). A 5-year backtest shows a typical error of ±62.6%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.10Projected 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 →
0.00–0.3195% 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 →
±62.6%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, Least Flycatcher in New Jersey is projected to stay roughly flat through 2029, near 0.10 (95% range 0.00–0.31). A 5-year backtest shows a typical error of ±62.6%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.100.000.31
20260.100.000.31
20270.100.000.31
20280.100.000.31
20290.100.000.31

Least Flycatcher Survey Routes in New Jersey

Routes recording Least Flycatcher in New Jersey.
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 →
Albion219681968
Croton219701970
Pottersville219891977
Sandbrook120071980
Holmansville119751975
New Bedford120071972
Hope119941976
Midvale120141971
Kemah Lake119921967
Bloomsbury120212003
High Point120241977
Dover119811977
Ramseysburg119991996
Roosevelt119991999

Least Flycatcher Population Trend in Other States

alaskaarkansascaliforniacoloradoconnecticutgeorgiaidahoillinoisindianaiowakentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanew-hampshirenew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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