...wheeliebins!
Have the city council provided the students[1] with wheelie bins yet?
[1] The whole time I was a student 2000-2007 the guild was constantly campaigning to get Selly Oak changed over from black bags to wheelie bins but the council just wouldn't do it.
It finally happened in late 2015:
https://yacf.co.uk/forum/index.php?topic=49529.msg1934361#msg1934361During the strike the wheeliebins couldn't cope and mountains of black bags accumulated. As this coincided with the start of term, the current generation of students don't appear to have learned the normal futility of leaving extra bags out.
But I don't think that explains the seagulls. The bin and random fly-tipping situation is broadly stable (indeed, the ones on our road were collected yesterday), but the swarm (it wasn't organised enough to be a flock) only lasted about half an hour.