ID tips & tricks
QUESTION OF SCALE
Seawatching can be tough. Problems come with distance (and distances can be vast, looking over an open sea), but also with a lack of context or anything to use to compare a bird with. If you can find any other known bird or object, such as a buoy or even a boat to compare an unknown bird with, it is a great help. Much of seawatching is about ‘jizz’, the general impression of a bird and its flight style; and with experience, assessing size becomes easier. However, for the inexperienced, there are plenty of pitfalls. It is easy, for instance, to mistake a distant Gannet, especially a young, brown one, for a larger shearwater, if you have no idea of scale. In reality, a Gannet is a much larger bird, with a wingspan of nearly 2m, and a total length of about nearly 100cm, whereas a Cory’s Shearwater has a wingspan of up to 126cm and is about 55cm long. Some seabirds, notably the storm-petrels, are particularly tiny, with a Storm Petrel being only about the size of a House Martin! So, be aware of this when trying to pick out distant birds.
One of the toughest challenges of all is separating the three smaller skua species. Great Skuas (also known as Bonxies) are relatively straightforward, but Arctic, Pomarine and Long-tailed Skuas are far from easy to identify, when not fully adult. All are surprisingly small birds (approximating to Common Gull sized) with considerable overlap between the species. Make detailed notes of structure and plumage where you can see it, as well as flight style. Pomarine Skuas look deep-bellied and heavy compared to relatively slim, slender winged Long-tailed Skuas, and Arctic Skuas fit rather neatly between, causing much potential confusion. Take a look at the three photos above and you can see how tough these skuas are to ID.