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Species · BCR 2 · BBS 2025 Release · 1966–2024

Cliff Swallow In BCR 2

All regionsBCR 2Aerial insectivores

Cliff Swallow in BCR 2 has surged: up 420% on the route-weighted index since 1995.

+420%Since 1995TrendPercent 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 →
8Routes 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 →

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 →

Cliff Swallow has surged in BCR 2: up 420% on the route-weighted index since 1995.

Routes In BCR 2

Routes recording Cliff Swallow in BCR 2.
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 →
Salmon LakeALASKA82004
TellerALASKA72024
CouncilALASKA42008
NomeALASKA32023
Cape NomeALASKA22008
Kanektok RivALASKA21995
St. Mary'SALASKA12002
Gweek RiverALASKA11999

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