I’ve just returned from 7-weeks of island hopping, data collecting and adventuring, all for one overlooked bird. So, it’s about time I introduced you to my study species, the Falkland Islands shag.
Confusingly, the species goes by many names: king shag, imperial shag, blue-eyed shag, Falklands shag, any of the above replacing ‘shag’ for ‘cormorant’… and is not to be confused with the Falklands' other of shag, the rock shag, which is a different species entirely. The Falklands shag is part of the imperial shag species complex (and it’s a complex issue indeed) – a group of seven very similar species, all with slight morphological differences and confined to different islands or regions across the subantarctic, from Patagonia to Crozet Island in the Indian Ocean. There is still a lot of debate as to whether each is it’s own unique species, or whether some are just different morphs of others. The Falklands shag, Leucocarbo atriceps albiventer, breeds primarily in the Falkland Islands, with some birds found also in nearby Patagonia.
A gregarious species, Falklands shag colonies can range from 100’s to 1000’s of nests, and can consist of just shags or be intermingled with breeding black-browed albatross and southern rockhopper penguins. The timing of the breeding season can be quite variable between colonies and years, but typically the birds start building nests in October and lay up to four eggs (but usually two or three) in November, which hatch around 29 days later after being incubated by both parents. The early breeding season is perhaps the most photogenic time to see the birds, as both males and females develop recurved crests on top of their head, the caruncles – knobbly growths at the top of their bill – swell and become bright orange, and the ring around their eye becomes an intense bright blue. Alongside their metallic navy and green plumage, this makes for a very beautiful bird. This type of ornamentation in wildlife is usually to indicate that the birds are ready to breed and are in a good, healthy condition, which can all help to attract a mate. In shags, these features start to disappear after they begin laying eggs, once the deal is done. Incredibly affectionate birds, each return to the nest involves a healthy amount of preening both of themselves and their partner being taking on the next parenting shift.
Shags make tall cone-shaped nests using seaweed and grass – frequently stealing materials from their neighbours' nests – and stick it all together with guano. They’ll often reuse the same nest sites between years, adding more nesting material every season, fixing any winter storm damage and making their little pedestals taller and taller. The nests can be so substantial that even if the colony decides to shift – which some seem to do periodically, for as yet unknown reasons – the old nests still scar the landscape years later, like an ancient civilisation.
Many people are quite familiar with the image of shags or cormorants resting on a rocky shore, wings outstretched, drying their feathers in the warmth of the sun. But Falklands shags don’t do this. As with other shag species, their plumage isn’t waterproof, so it’s a wonder that they don’t get cold, especially after diving in chilly subantarctic waters. But it’s thought that because they have such a dense layer of downy feathers the cold water never penetrates far enough to chill them, so the cost of standing with outstretched wings in the relentless winds of the South Atlantic just isn’t worth it. As long as they keep their feathers in good condition, achieved by spending a lot of time preening, then the birds remain toasty. In fact, despite the winds, sometimes the birds can get too hot. If you visit a colony when the sun is shining, which is actually quite often during the summer, you might notice the shags with their mouth open, fluttering what’s known as a gular pouch – essentially, the area at the top of their neck which they can expand – to help cool themselves down.
Despite them being a familiar sight across the Falkland Islands, not very much is known about the Falklands shag. So if you’re feeling suitably enamoured with the birds and want to be the first to hear the latest updates on my research and Falkland adventures, pop your email in the box below.