BirdAnalyst
Species · BCR 12 · BBS 2025 Release · 1966–2024

Merlin In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGeneralists

Merlin in Boreal Hardwood Transition has surged: up 460% on the route-weighted index since 1974.

+460%Since 1974TrendPercent 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 →
69Routes 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 →
38YearsYears 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 →

Merlin has surged in Boreal Hardwood Transition: up 460% on the route-weighted index since 1974.

Merlin In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Merlin in Boreal Hardwood Transition is projected to rise about 81% by 2029 — from 0.07 in 2024 to a central estimate of 0.12 (95% range 0.05–0.19). A 5-year backtest shows a typical error of ±42.8%, with 60% of held-out values landing inside the 95% band.

+81%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 →
0.12Projected 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 →
0.05–0.1995% 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 →
±42.8%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, Merlin in Boreal Hardwood Transition is projected to rise about 81% by 2029 — from 0.07 in 2024 to a central estimate of 0.12 (95% range 0.05–0.19). A 5-year backtest shows a typical error of ±42.8%, with 60% of held-out values landing inside the 95% band.19682029
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 →
20250.110.040.18
20260.110.050.18
20270.120.050.18
20280.120.050.19
20290.120.050.19

Routes In Boreal Hardwood Transition

Routes recording Merlin in Boreal Hardwood Transition.
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 →
CunardMICHIGAN32021
DebsMINNESOTA32023
IrmaWISCONSIN32010
Gibbs CityMICHIGAN22021
IshpemingMICHIGAN22021
Hubbard LakeMICHIGAN21988
Sherry LakeMINNESOTA22022
Crane LakeMINNESOTA22023
ChaffeyWISCONSIN22022
ShanagoldenWISCONSIN22007
Eagle RiverWISCONSIN22021
Amnicon FallsWISCONSIN22023
CavourWISCONSIN22019
OntonagonMICHIGAN12018
BerglandMICHIGAN12022
MareniscoMICHIGAN12014
BootjackMICHIGAN12023
Ned LakeMICHIGAN12015
HermanMICHIGAN12015
Brocky LakeMICHIGAN12023
ShingletonMICHIGAN12012
MuskallongeMICHIGAN12022
TahquamenonMICHIGAN12011
GilchristMICHIGAN12018
Skegemog PtMICHIGAN12019

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