Scientists solve mystery behind how gannets hunt for fish

Gannets travel hundreds of miles to source food for their chicks

New research has shed light on how gannets choose the best spot in the ocean to search for fish.

The largest seabirds in the North Atlantic can travel hundreds of miles from their homes just to catch food.

But with around a million square miles of ocean to choose from, it has always been a mystery how they decide where to take the plunge.

Now a Glasgow University study has found gannets learn to hunt by following their elders.

Scientists recorded thousands of the seabirds commuting to and from the Bass Rock, in the outer part of the Firth of Forth in the east of Scotland.

The rock is home to the world's largest northern gannet colony - an estimated 75,300 breeding pairs.

Dr Ewan Wakefield, from the university's Institute of Biodiversity, Animal Health and Comparative Medicine, said: "Our research offers a more detailed insight into how and why gannets search for food in the way they do.

"With such a large expanse of ocean to choose from it has always been a mystery as to how they know where fish are most likely to be found.

"By demonstrating that young gannets follow more experienced adults, we have shown that knowledge about the best feeding grounds may be being passed down from generation to generation."

'Communal wisdom'

The team observed gannets commuting to and from the Bass Rock from the Isle of May, Fife Ness and St Abbs Head.

They then modelled how frequently the gannets travelled in flocks, the sizes of those flocks and the positions of young and adult birds.

Birds travel in flocks for a number of reasons, including to reduce aerodynamic drag and therefore save energy.

In addition, travelling in a group can improve hunting efficiency, navigational accuracy and predator avoidance.

The research also demonstrated that travelling in flocks may also facilitate social learning too.

Dr Wakefield said: "The ability to tap into this communal wisdom may also go some way to explaining why gannets and other seabirds breed in such huge colonies."

The study, Immature gannets follow adults in commuting flocks providing a potential mechanism for social learning, is published in the Journal of Avian Biology.