Caspian Tern
The Caspian tern (Hydroprogne caspia) is a species of tern, with a subcosmopolitan but scattered distribution. Despite its extensive range, it is monotypic of its genus, and has no accepted subspecies. The genus name is from Ancient Greek hudros, "water", and Latin progne, "swallow". The specific caspia is from Latin and, like the English name, refers to the Caspian Sea.
Wikipedia ↗Wingspan and trait data: Fox et al. (2026), CC BY 4.0; incorporating AVONET (Tobias et al. 2022) and BirdWingData (Shiomi et al. 2025)
By hour of day
Counts reflect vocal activity and ambient noise, not abundance.
Recent days
Daily counts. Seasonal bars replace this once there is a year of records to draw them from.
Where heard
Home and away are counted separately everywhere except here.
Where it lives
Breeding and resident range, from BirdWeather. Not where you have heard it — that is the map on the Outings page.
Elsewhere
Recordings
Highest-confidence detections first. Confidence is a threshold, not a probability of being correct.