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

Black Tern Population Trend in Colorado

All statesWetland birds

Black Tern in Colorado has held roughly steady: down 6% on the route-weighted index since 1993.

-6%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 →
4Routes 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 Black Tern Trends in ColoradoNotable 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 Black Tern in Colorado. See the full index history below.

Black Tern Survey Routes in Colorado

Routes recording Black Tern in Colorado.
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 →
Briggsdale1519951995
Alamosa920231989
Julesburg420022002
Edler119941994

Black Tern Population Trend in Other States

californiaidahoillinoisindianaiowakansasmainemichiganminnesotamissourimontananebraskanevadanew-yorknorth-dakotaohiooregonsouth-dakotatexasutahwashingtonwisconsinwyoming

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