Fish follow friends to find new food sources

Published: 8 July 2014 at 15:53

Research by Anglia Ruskin scientist examines the social behaviour of sticklebacks

Many people follow recommendations from their friends to find the best places to eat – and new research has shown that fish do the same.

The study by scientists at Anglia Ruskin University, the University of St Andrews and McMaster University in Canada has discovered that familiarity between members of a shoal of sticklebacks (Gasterosteus aculeatus) affects both social organisation and the discovery of food.

The researchers caught 80 three-spined sticklebacks, a common native species found in rivers across the UK.  The sticklebacks were separated into two groups for six weeks, which is enough time for them to develop recognition of their group mates.  They were then tagged and videoed as they were set tasks to discover new food locations.

The results show that familiarity between shoal members had a clear effect on their ability to find food, with sticklebacks more likely to discover the food source if a member of the same shoal had also previously found it.

The mechanism by which familiarity affects behaviour in fish is not fully clear, although the scientists believe it may reflect a bias for observing, or more strongly responding to, the behaviour of familiar individuals.

Dr William Hoppitt, Senior Lecturer in Zoology at Anglia Ruskin University, said:

“Our results provide evidence of an effect of familiarity upon group social organisation, with fish being more likely to associate with familiar than with unfamiliar individuals.
“Furthermore, familiarity was seen to affect the likelihood of an individual discovering a foraging task, with strong evidence of a social effect on discovery of the foraging tasks, such that individuals tended to discover the food sooner if a familiar individual from their group had previously done so.
“These results demonstrate that factors that affect social interactions can influence how individuals encounter and exploit resources, and suggests that researchers should take into account social factors when investigating how information and behaviour spread through different populations.”

The full article is published tomorrow [00.01am on Wednesday, 9 July] in Proceedings B, the Royal Society’s flagship biological research journal.