Sunday, April 28, 2013

"Pinning down" the skuas. As at 24th April, 2013.

At various points since I last wrote a Blog ( on 13th April, apologies! ) I've completed some seawatching sessions with the single objective of checking the situation here on Islay for passage skuas, set against that enjoyed on the Solway Firth.

As early as the 15th April three skua species ( not Long-tailed ) were noted coming into the eastern end of the Solway Firth and then leaving overland with the apparent intention of taking a "short cut" to the North Sea. At other intervals since then, small numbers of Great and Pomarine Skuas have been recorded there, including a party of eight Pomarine Skuas on the 18th.  Birds tend to link to the incoming tide , which suggest they are out there in the southern confines of the Irish Sea and then move into the Firth itself.  I find all this utterly fascinating. Of course, passage over land masses by skuas is not unknown, indeed even Switzerland has some skua records within its files!!!

But what of early passage skuas from Islay? I suspect weather plays a great part in their occurrences, but attempts so far to determine whether there is a regular passage at this time of year suggest such not to be the case. Certainly birds appear here in early - mid May, but from what breeding population is anyone's guess. Strong westerlies forcing birds into the Irish Sea, from which a proportion filter north is a safe guess as to routes being taken, in other words birds are there by default rather than design. Certainly observations made here produce nothing to match, in parallel, the passage being witnessed through the Solway Firth.  Birds could be missed, of course, and visibility clearly has a  major part to play. The situation in autumn appears to be different as birds filter southwards through the islands and are easily seen. By contrast, the well documented passage of Pomarine and Long-tailed Skuas in Spring off the Outer Hebrides suggests a majority of those birds pass west of Ireland  and then "cut across" towards the north west mainland of Scotland. In the meantime, the occurrence of a few skuas here would bring as much enjoyment as witnessing a sustained passage!!

It has also to be said that the sessions weren't a waste of time in a birding context, as passage Grey lag Geese, Light -bellied Brent Geese, Red-throated Diver, Great Northern Diver were all noted as well as those true conveyors of Spring, Whimbrel, whose tinkling calls expressing relief at reaching land or announcing a presence to others of their species,  are a seasonal joy from which I always draw delight each and every year. In addition, the ever varied parade of more local sea birds from Fulmars, Shags and Kittiwakes, to the daily processions of Gannets ensure a reliable backdrop. One morning produced a passage of over 2000 Auks in 90 minutes as long strings of birds , mainly Razorbills, winged their way to more northerly breeding areas.   I'm minded to mention that this Spring has not been for the faint hearted as far as seawatching is concerned. Crouched in some hollow ( what a luxury!!! ), close to the sea, in a withering cold wind caused a few doubts to be cast on its enjoyment rating!!!
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