BirdAnalyst
Species · BCR 4 · BBS 2026 Release · 1966–2025

American Dipper In BCR 4

All regionsBCR 4Wetland birds

American Dipper in BCR 4 has fallen sharply: down 51% on the route-weighted index since 2000.

-51%Since 2000TrendPercent 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 →
5Routes 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 →

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 →

American Dipper has fallen sharply in BCR 4: down 51% on the route-weighted index since 2000.

Routes In BCR 4

Routes recording American Dipper in BCR 4.
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 →
Chatanika RALASKA12022
CantwellALASKA12018
Hatcher PassALASKA12025
Chena Hot Spring 2ALASKA12010
Nabesna RoadALASKA11990

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.