BirdAnalyst
Species · Maryland · BBS 2026 Release · 1966–2025

Acadian Flycatcher Population Trend in Maryland

All statesAerial insectivores

Acadian Flycatcher in Maryland has surged: up 172% on the route-weighted index since 1968.

+172%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 →
76Routes 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 →
59YearsYears 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 MarylandNotable 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 Maryland: up 172% on the route-weighted index since 1968.

Acadian Flycatcher Population Forecast in Maryland

If the recent trend holds, Acadian Flycatcher in Maryland is projected to stay roughly flat through 2030, near 8.5 (95% range 6.7–10). A 5-year backtest shows a typical error of ±15.7%, with 60% of held-out values landing inside the 95% band.

-2%Change by 2030TrendPercent 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 →
8.5Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
6.7–1095% 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 →
±15.7%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, Acadian Flycatcher in Maryland is projected to stay roughly flat through 2030, near 8.5 (95% range 6.7–10). A 5-year backtest shows a typical error of ±15.7%, with 60% of held-out values landing inside the 95% band.19662030
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 →
20268.16.49.9
20278.26.510.0
20288.36.610
20298.46.710
20308.56.710

Acadian Flycatcher Survey Routes in Maryland

Routes recording Acadian Flycatcher in Maryland.
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 →
Pomonkey4920251966
Earlton4820242014
Island Creek4820251991
Hughesville2720251966
Smithsburg1920141972
Davidsnville1920251982
La Plata1720091966
Millington1620251969
Ijamsville1620251986
Pomfret1520241966
Forest Grove1420232011
Nottingham1420252005
Oldtown1320251970
Wolfsville1220251966
Pt Republic1219891966
Tall Timbers1020141966
Cokesbury1020251967
Madonna1020222009
St. George'S Island920172015
Green Ridge820251995
Furnace Town820252015
Berlin820251980
Floyd720251967
Emmitsburg720251967
Cheltenham720041966

Acadian Flycatcher Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamassachusettsmichiganminnesotamississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvirginiawest-virginiawisconsin

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.