Bottlenose dolphins live in groups called pods, which are a bit like extended families. In the Adriatic around the island of Lošinj, researchers have identified over 150 individual dolphins by their dorsal fins - the fin on top of the back. Each fin has a unique shape, like a fingerprint, with nicks and notches that scientists photograph to tell individuals apart.
Adriatic dolphins are excellent hunters. They work in teams to herd fish into tight balls near the surface, then take turns rushing through to catch them. Some dolphins have learned to follow fishing boats and snap up fish that escape the nets - a cheeky habit that the fishermen mostly forgive.
Dolphins are among the most playful animals in the world. They surf the bow waves of boats, leap just for fun, and have been observed playing with pieces of seaweed. Young dolphins play-fight and chase each other through the underwater rock formations off the Croatian islands.
The waters around Lošinj have been a protected dolphin reserve since 2006. The reserve monitors the dolphins' health, studies their communication - dolphins use complex clicks and whistles to talk to each other - and helps boats navigate carefully so the dolphins are not disturbed during feeding or resting.