December 30th

There were over 30 great black-backed gulls roosting on the rocks by the harbour at high tide today. Great black-backs are much less common than herring gulls in most places but they outnumber them around the harbour. There are about 10 herring gulls for every great black-backed gull in the UK during the winter, with about 70,000 having been counted country-wide. We have about 20,000 pairs breeding which is about 10% of the world population. Numbers have been stable for the last 30 years. They are our biggest gull species and are clearly much bigger and bulkier when standing next to a herring gull. It is probably a very good job that great black-backs don’t favour nesting on rooftops: they are much warier of people than herring gulls but out at sea they are hugely aggressive and powerful, killing and eating most other seabirds. During the summer they also take a lot of herring gull chicks and eggs. Herring gulls may well be taking advantage of the absence of their main predator when they choose to nest in towns. Great black-backed gulls are mostly scavengers though, following the lobster boats out and taking first pick of the discarded bait or the bycatch tossed from the creels. This is the main reason of course why we have so many around Crail harbour.

Great black-backed gull