... is that they eat guillemot eggs. Here's a picture taken by Ann Lowe last week:
That is one big guillemot egg breakfast. However, I've decided to forgive the herring gulls for now, as we all have to eat...
In other news, I've found the peregrine nest! At least, I think it is a nest - it is quite precariously positioned - but there was definitely a nervous, screeching female sitting on it, eyeing me with disdain, So I'll watch carefully over the next few weeks to see if any eggs appear.