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

Willow Flycatcher In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainAerial insectivores

Willow Flycatcher in Lower Great Lakes / St. Lawrence Plain has risen sharply: up 67% on the route-weighted index since 1968.

+67%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 →
84Routes 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 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 →

Willow Flycatcher has risen sharply in Lower Great Lakes / St. Lawrence Plain: up 67% on the route-weighted index since 1968.

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

If the recent trend holds, Willow Flycatcher in Lower Great Lakes / St. Lawrence Plain is projected to rise about 47% by 2029 — from 2.5 in 2024 to a central estimate of 3.7 (95% range 1.6–5.7). A 5-year backtest shows a typical error of ±69.9%, with 80% of held-out values landing inside the 95% band.

+47%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 →
3.7Projected 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 →
1.6–5.795% 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 →
±69.9%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, Willow Flycatcher in Lower Great Lakes / St. Lawrence Plain is projected to rise about 47% by 2029 — from 2.5 in 2024 to a central estimate of 3.7 (95% range 1.6–5.7). A 5-year backtest shows a typical error of ±69.9%, with 80% 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 →
20253.61.65.7
20263.61.65.7
20273.61.65.7
20283.71.65.7
20293.71.65.7

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Willow 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 →
CastileNEW-YORK142024
WatertownNEW-YORK122012
HarmonsburgPENNSYLVANIA122023
NashvilleNEW-YORK112018
PittsfieldOHIO102024
GarrettsvileOHIO101991
HiramOHIO102021
E YoungstownNEW-YORK92023
CayugaNEW-YORK62024
SalemNEW-YORK62024
N VictoryNEW-YORK61972
LucerneOHIO62024
OrleansNEW-YORK52024
St JohnsburgNEW-YORK52018
Ferris CrnrsPENNSYLVANIA52024
BristolVERMONT52000
RhinebeckNEW-YORK42022
BranchportNEW-YORK42024
Canadice LNEW-YORK42014
SheridanNEW-YORK42024
PenfieldNEW-YORK42024
N Victory 2NEW-YORK42019
Cicero CtrNEW-YORK42024
N WilmurtNEW-YORK41998
PhiladelphiaNEW-YORK42024

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