04.04.2026 – Terns

During the day, both boats were encountering Bottlenose dolphins (Tursiops truncatus), Short-beaked common dolphins (Delphinus delphis) and Loggerhead sea turtles (Caretta caretta).

However, the afternoon guests on Stenella had a very different encounter  – a few miles offshore, they came across two Common terns (Sterna hirundo). Known for their impressive migrations, these birds often nest on sandy or gravelly beaches, islands, or riverbanks, which makes them very vulnerable to human disturbance. If breeding birds are scared off, eggs can only survive if their temperature stays between 30–35°C; lower or higher temperatures will kill the embryo.

You can distinguish them from the very similar-looking Arctic tern (Sterna paradisaea) by their bill, which is longer and has a black tip.

By Eva Köhle

Sightings of the day

Ribeira Brava

09:00 Short-beaked common dolphin, Bottlenose dolphin

13:00 Bottlenose dolphin, Loggerhead sea turtle

Stenella

09:30 Short-beaked common dolphin, Bottlenose dolphin

13:30 Bottlenose dolphin, Loggerhead sea turtle, Common tern