They're called common murres...

and it's not difficult to agree that they are indeed very common on Tyuleniy, a non-volcanic island that consists of folded sandstones rising from the sea:

I'll leave it to you to make a headcount, but the murre population is estimated to be approximately 200,000:

Here's an adult murre with a fish for its chick:

And here are a couple of squabbling gulls: