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Species · Maryland · BBS 2025 Release · 1966–2024

Least Flycatcher Population Trend in Maryland

All statesAerial insectivores

Least Flycatcher in Maryland has collapsed: down 75% on the route-weighted index since 1968.

-75%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 →
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 →
58YearsYears 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 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 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 collapsed in Maryland: down 75% on the route-weighted index since 1968.

Least Flycatcher Population Forecast in Maryland

If the recent trend holds, Least Flycatcher in Maryland is projected to rise about 76% by 2029 — from 0.07 in 2024 to a central estimate of 0.13 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±109.7%, with 100% of held-out values landing inside the 95% band.

+76%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 →
0.13Projected 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 →
0.00–0.3495% 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 →
±109.7%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, Least Flycatcher in Maryland is projected to rise about 76% by 2029 — from 0.07 in 2024 to a central estimate of 0.13 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±109.7%, 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 →
20250.140.000.35
20260.130.000.34
20270.130.000.34
20280.130.000.34
20290.130.000.34

Least Flycatcher Survey Routes in Maryland

Routes recording Least 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 →
Vindex220221966
Accident220101992
Finzel220241995
Floyd120181966
Mt Nebo119911970
Smithsburg119971997
Wolfsville119801980
Easton119711971
Silver Spg119661966
Accident 2120212021
Randallstown119771977
Jennings120241995
Van Bibber119821978
Steyer120211996

Least Flycatcher Population Trend in Other States

alaskaarkansascaliforniacoloradoconnecticutgeorgiaidahoillinoisindianaiowakentuckymainemassachusettsmichiganminnesotamissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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