Dexterous Herring Gulls learn new tricks to adapt their feeding habits
By University of Southampton
Observations of Herring Gulls by scientists from the University of Southampton have shown how the coastal birds have developed complicated behaviour to ‘skin’ sea creatures to make them safe to eat. Researchers think this feeding habit may be a response to urbanisation and changes in food availability.
The gulls (Larus argentatus) of Dún Laoghaire Marina at Dublin in Ireland have found a novel way of disposing of the tightly fixed outer layer of sea squirts – an organism which they have learnt to pluck from the underside of pontoons by diving or floating on the water.
Sea squirts, or ascidians, are filter feeding creatures which have an outer layer, known as a ‘tunic’, designed to give protection from predators. This tunic is unpalatable to gulls, however, those living around Dún Laoghaire have overcome this using a particularly clever method.
The birds grasp the sea squirt’s tunic in their beaks, shake it to loosen the soft edible inner body, then switch to hold the inner body (again with their beaks) and shake again until the inedible outer layer is removed.
The team’s report, published in the journal Ecosphere, is the first recorded observation of Herring Gulls feeding using this unusual behaviour.
Read more here: https://www.southampton.ac.uk/news/2019/05/clever-seagulls.page