BirdAnalyst
Species · BCR 13 · BBS 2025 Release · 1966–2024

Least Flycatcher In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainAerial insectivores

Least Flycatcher in Lower Great Lakes / St. Lawrence Plain has fallen sharply: down 61% on the route-weighted index since 1968.

-61%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 →
83Routes In RegionSurvey 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 SignalsNotable 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 Lower Great Lakes / St. Lawrence Plain: down 61% on the route-weighted index since 1968.

Least Flycatcher In Lower Great Lakes / St. Lawrence Plain Population Forecast

If the recent trend holds, Least Flycatcher in Lower Great Lakes / St. Lawrence Plain is projected to fall about 35% by 2029 — from 0.94 in 2024 to a central estimate of 0.61 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±34.5%, with 100% of held-out values landing inside the 95% band.

-35%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 →
0.61Projected 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 →
0.00–1.795% 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 →
±34.5%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, Least Flycatcher in Lower Great Lakes / St. Lawrence Plain is projected to fall about 35% by 2029 — from 0.94 in 2024 to a central estimate of 0.61 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±34.5%, 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 →
20250.800.001.9
20260.750.001.8
20270.700.001.8
20280.660.001.7
20290.610.001.7

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Least Flycatcher in Lower Great Lakes / St. Lawrence Plain.
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 →
West BangorNEW-YORK151999
ShaftsburyVERMONT152024
BalmatNEW-YORK112008
NashvilleNEW-YORK72018
FowlerNEW-YORK71968
PulaskiNEW-YORK62024
N WilmurtNEW-YORK61998
North PownalVERMONT62018
HinesburgVERMONT61994
N VictoryNEW-YORK51972
BristolVERMONT52018
AusterlitzNEW-YORK42024
MendonNEW-YORK41994
AkeleyPENNSYLVANIA41979
Sugar GrovePENNSYLVANIA42023
W ShokanNEW-YORK32019
DuanesburgNEW-YORK32021
CastileNEW-YORK32024
ClintonNEW-YORK32002
HopkintonNEW-YORK32021
RhinebeckNEW-YORK22024
GhentNEW-YORK22017
Ballston LkNEW-YORK21970
TrumansburgNEW-YORK22015
RushvilleNEW-YORK22018

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