A new study has shown that tiger sharks- a species widely regarded as a solitary, nomadic predator of the sea- have social preferences for one another.
A team of conservation scientists looking at the impact of tourism on tiger sharks have, for the first time observed them in social groups near an area called Tiger Beach off the north-west side of Little Bahama bank in the Bahamas, a popular spot for tourists.
Published today (Friday 3rd September) in Frontiers in Marine Science, the study, led by ZSL’s Institute of Zoology, Lancaster University and the University of Miami Rosenstiel School of Marine and Atmospheric Science (UM), reveals that tiger sharks appear to choose and form social groups – a contrast to previous understanding – but that their social preferences for each other tend to break down when they are exposed to bait provided by shark diving experiences, at Tiger Beach.
Baited shark dives are often conducted by dive tourism companies around the world to attract the animals so that tourists may observe them. This approach has been criticised by some conservationists and shark experts, due to the possible long-term impacts on the predators, including changes to their natural hunting behaviour.
A pioneering study
This study is the first of its kind to look at the influence of bait feeding on the social behaviour of tiger sharks. Although the study reveals that interactions between the sharks seem to become more random when food is provided, the sharks did exhibit a ‘take it or leave it’ attitude to the bait feeding, suggesting that the impacts on their social behaviours are not long-lasting. The study says that if the frequency of tourism activity doesn’t increase, sharks could likely retain natural behaviours when not being fed and avoid dependence.
David Jacoby, ZSL Honorary Research Associate, now at Lancaster University and lead author of the study said: “The boundary between wildlife and people is becoming increasingly thin, so as well as observing a new social behaviour for the first time in what was once thought of as a solitary shark, we also measured the impacts of human activity on these predators’ interactions. Luckily, they seem to show some resilience to the bait feeding.”
The tiger sharks were observed using a mixture of acoustic tracking data as well as social network analysis of behaviour over three years.