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

Cerulean Warbler In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionForest birds

Cerulean Warbler in Boreal Hardwood Transition has declined: down 34% on the route-weighted index since 1994.

-34%Since 1994TrendPercent 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 →
10Routes 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 →
12YearsYears 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 →

No notable trend signals for Cerulean Warbler in Boreal Hardwood Transition. See the full index history below.

Routes In Boreal Hardwood Transition

Routes recording Cerulean Warbler 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 →
Eagle RiverWISCONSIN31995
IsabellaMICHIGAN12008
Sand LakeMICHIGAN12021
Tamarac NwrMINNESOTA12003
ChaffeyWISCONSIN11997
Grand ViewWISCONSIN12003
MontrealWISCONSIN11984
CouderayWISCONSIN11999
CrandonWISCONSIN11997
AmbergWISCONSIN11999

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