My TL;DR:

Experts say a series of storms in October, culminating in Storm Babet, had caused the disappearance – and likely death – of these birds.

Records for the island have been kept since the mid-1970s, and there has never been such a heavy loss.

Shags feed within a mile of the coast but strong easterly winds stirred up the sea, which meant they could not hunt for days on end. They carry little fat because it reduces their ability to dive, and so die if they do not feed regularly.

The climate crisis is likely to make these events more frequent, and more destructive.

UKCEH is calling on people to report and send photos of any dead shags with coloured rings on to shags@ceh.ac.uk.