July’s bird of the month is the black guillemot. Non-birders are probably not as familiar with this dapper little auk as its showbiz cousin the puffin. It is probably also less well known than the common guillemot and razorbill due to its much smaller range. However, it is a fascinating seabird and approaches life in a significantly different way from the other UK representatives of the auk family. Shetland has one of Scotland’s biggest concentrations, so I have had lots of opportunities to watch this lovely bird.
Two Birds in One
Black guillemots, or ‘tystie’ in the Shetland dialect, have two distinct plumages. Like our other auks, they moult at the end of the breeding season and change their appearance completely. If you didn’t know any better, you might even think they were two different species.
In the summer, adults are black with a large white patch on the wings. This gives them a very smart and dashing appearance. In addition, their legs and feet are a beautiful bright red that really contrasts with the black body. When they open their beaks, you can see that their gape is also bright red. Both sexes look identical. If you are lucky enough to see them stood on a pier or buoy, they look like little dinner-suited penguins.
The autumn moult produces a very different look. Winter adults are mostly pale grey and white with some black barring. The beak stays black, and the white wing patch stays, although this stands out less against the paler body plumage now. The legs and feet also become a paler red colour. It is almost as though someone made a negative image of a summer tystie.
An Auk with a Difference
As I mentioned earlier, the tystie approaches life in a different way from the UK’s other breeding auks. One difference is that they don’t tend to form large breeding colonies like their relatives, preferring to nest singly or in very small groups. These nests are well hidden in crevices, caves and among boulders, as well as sometimes within piers and harbour walls. They are also much more likely to forage for fish and crustaceans near the nest site in the summer. This is unlike our other auks who often fly great distances to find food for their chicks.
Another big difference is that they don’t migrate out to sea at the end of the breeding season but stay largely in the same place all year. In contrast, common guillemots, razorbills and puffins head out to the North Atlantic and North Sea for the winter. They then only return to their breeding grounds in the spring.
Black guillemots also have a very unusual sound in comparison with their UK relatives. Although their cousins’ calls are different from each other, they are all low, guttural sounds of one sort or another. These range from the puffin and razorbill’s growling noises to the guillemot’s cooing or purring. The tystie, however, makes a very high-pitched whistling sound that can sometimes even sound a bit eerie and is definitely not like any noise our other auks make.
The UK’s black guillemots are mostly found on Scotland’s rocky coasts. There are smaller populations in Northern Ireland and the Isle of Man and tiny numbers also breed in North Wales and Cumbria. This range is much more restricted than the other members of the family. In addition to breeding on Welsh and Scottish coasts, puffins, guillemots and razorbills also have English colonies in the West Country, Yorkshire and Northumbria.
Because they are resident and non-migratory, if you live in or visit Scotland at any time of year, you have a very good chance of seeing this beautiful seabird. I love their relatives as much as anyone (you would have to have a heart of stone not to fall for a growling puffin, after all), but these smart little northern penguin lookalikes are an underrated gem.