From pilfering chips to swallowing whole starfish, gulls are known for their voracious appetites.
However, one scientist was so astounded to see pictures on social media of gulls eating "weird and wonderful things" that she launched a citizen science project to study their shifting diets.
University of Salford ecologist Dr Alice Risely wants people to upload their snaps of hungry gulls to the project's website, Gulls Eating Stuff.
"By studying gulls' diet, we can learn more about their behaviour, their role in ecosystems and the pressures they face in a changing world," she said.