BirdAnalyst
Species · South Carolina · BBS 2025 Release · 1966–2024

Least Tern Population Trend in South Carolina

All statesWetland birds

Least Tern in South Carolina has edged down: down 22% on the route-weighted index since 1999.

-22%Since 1999TrendPercent 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 →
3Routes In StateSurvey 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 Least Tern Trends in South CarolinaNotable 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 Least Tern in South Carolina. See the full index history below.

Least Tern Survey Routes in South Carolina

Routes recording Least Tern in South Carolina.
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 →
Johns Isle219741974
Hardeeville220242019
Kiawah Island120211998

Least Tern Population Trend in Other States

alabamaarkansascaliforniacoloradodelawarefloridageorgiaillinoiskansaskentuckylouisianamainemarylandmassachusettsmississippimissourinebraskanew-jerseynew-yorknorth-carolinaoklahomatennesseetexasvirginia

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