BirdAnalyst
Species · Louisiana · BBS 2025 Release · 1966–2024

Caspian Tern Population Trend in Louisiana

All statesWetland birds

Caspian Tern in Louisiana has edged down: down 17% on the route-weighted index since 1971.

-17%Since 1971TrendPercent 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 StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
16YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Caspian Tern Trends in LouisianaNotable 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 Caspian Tern in Louisiana. See the full index history below.

Caspian Tern Survey Routes in Louisiana

Routes recording Caspian Tern in Louisiana.
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 →
Ltl Chenier720142014
Gran Chenier519731970
Grand Isle420182010
Berwick320111991
Brousville220002000
Kraemer120002000
Creole119701967
Sabine Nwr 2120152013

Caspian Tern Population Trend in Other States

alabamaalaskacaliforniadelawarefloridaidahoillinoisindianamarylandmichiganminnesotamontananevadanorth-carolinanorth-dakotaoregonsouth-carolinatexasutahvermontvirginiawashingtonwisconsinwyoming

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