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

Acadian Flycatcher Population Trend in New Jersey

All statesAerial insectivores

Acadian Flycatcher in New Jersey has surged: up 459% on the route-weighted index since 1969.

+459%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 →
27Routes 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 →
50YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Acadian 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 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 →

Acadian Flycatcher has surged in New Jersey: up 459% on the route-weighted index since 1969.

Acadian Flycatcher Population Forecast in New Jersey

If the recent trend holds, Acadian Flycatcher in New Jersey is projected to fall about 25% by 2029 — from 0.57 in 2024 to a central estimate of 0.43 (95% range 0.21–0.65). A 5-year backtest shows a typical error of ±33.5%, with 60% of held-out values landing inside the 95% band.

-25%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 →
0.43Projected 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 →
0.21–0.6595% 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 →
±33.5%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, Acadian Flycatcher in New Jersey is projected to fall about 25% by 2029 — from 0.57 in 2024 to a central estimate of 0.43 (95% range 0.21–0.65). A 5-year backtest shows a typical error of ±33.5%, with 60% 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 →
20250.400.190.62
20260.410.190.63
20270.420.200.63
20280.420.200.64
20290.430.210.65

Acadian Flycatcher Survey Routes in New Jersey

Routes recording Acadian 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 →
Pomona620241979
Estell Manor520222022
Hope419941994
Kemah Lake320241981
High Point220231987
Winslow220241992
Woodbury Hgt120231994
Greenwich120101966
Six Points120132013
Spraguetown 2120052000
Albion120102006
Bennett Mill119981991
Holmansville120042004
New Bedford120162016
Midvale120051994
Bloomsbury119871987
Dover120051991
Pottersville119881988
Keyport120032002
Cranbury119951995
Friendship120191978
Pedricktown 2120162016
Cape May Ch120061994
Pedricktown120111993
Spraguetown 3120232023

Acadian Flycatcher Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamarylandmassachusettsmichiganminnesotamississippimissourinew-hampshirenew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvirginiawest-virginiawisconsin

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