BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Harlequin Duck In Northern Rockies

All regionsNorthern RockiesWaterfowl

Harlequin Duck in Northern Rockies has declined: down 38% on the route-weighted index since 1993.

-38%Since 1993TrendPercent 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 →
6Routes 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 →
15YearsYears 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 Harlequin Duck in Northern Rockies. See the full index history below.

Routes In Northern Rockies

Routes recording Harlequin Duck in Northern Rockies.
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 →
YellowstoneWYOMING32022
Logan PassMONTANA22018
Marble CreekIDAHO12010
FeathervilleIDAHO11998
Ne EntranceWYOMING12000
Hunter PeakWYOMING12000

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