Friday, August 31, 2012

Grey lag Goose survey ! 28.8.2012.

Well, finally, the actual  "day" arrived after time being taken up previously with reconnaissance checks, coverage arrangements and the like. Fortunately the weather had improved too, following the poor showing over the couple of days beforehand. Today dawned fine, although some quite heavy rain showers developed later!

You may have seen previous entries on this subject as, for several years now, I've completed a survey  when the autumn accumulation of birds occurs on Islay. The early years were easy as the birds chose a limited number of spots and all of these could be easily monitored. Nowadays it's more of an island wide operation with several other people involved on the day in order to secure a complete picture.

When I first came to Islay in 1999 there was only a handful of breeding pairs of Grey lag Geese present and virtually all of them were around Loch Gorm, which was quite convenient given the house overlooked the whole area. Gradually numbers increased and autumn gatherings began to reach the low hundreds. It must be mentioned here that, in many respects, Islay is a potential paradise when it comes to the availability of breeding sites. These range from innumerable isolated lochans to offshore islands and islets and endless bits of suitable rough areas in between!!  In the early years the wintering population, largely remained close to where I now live in the south west of the island, was relatively static and numbered around a hundred or so, indicating some birds left and returned the following Spring. There has been much conjecture about the increase over the years, although I tend to think the solution is quite simple. In the early years there was never any real check on breeding numbers and I believe these increased exponentially, season after season, possibly recruiting "new blood" as birds returned after the winter ( from where,we don't know incidentally!! ). Small numbers of non-breeding birds were encountered and, in parallel, the breeding numbers continued to increase until, at its highest point the autumn gathering reached over 2,500. Following the moult the birds appeared to vacate many areas and congregate in the north of the island around Loch Gruinart and at the head of Loch Indaal.  As new feeding areas became available they became frustratingly mobile, but opportunities always arose to monitor "the assembled flock" when it chose to concentrate its activities at a small number of sites, which were close to one another, or at roost.

Now, of course, interest began to be raised as concentrated feeding on areas used by the wintering  populations of Barnacle and Greenland White-fronted Geese wasn't seen as desirable!! And, of course, from a farming viewpoint, the geese were seen as affecting managed pastures for cattle and sheep just as much as the above wintering birds. The situation also became complicated as undoubtedly Grey lag Geese on passage use Islay and fluctuating numbers occurred. Evidence for this came from first hand accounts at the RSPB reserve at Gruinart and birds actually seen passing  at sea along Islay's western coastline or down the Sound of Islay. Whatever the derivation, or the theorising, the fact remained that we were seeing increasing breeding numbers present on the island resulting in a similar increasing number in autumn. The extent to which these were supplemented by passage birds, moved off themselves, or remained in increasing numbers, was academic to many set against what was seen as an increasing problem affecting farming enterprises. As an aside, the numbers remaining in winter are beginning to be around 50% of the total congregation seen in autumn. Where the absent birds move to is anybody's guess and possibly a subject which will only be resolved when a sample of birds is caught and fitted with numbered collars which can be observed and reported upon.

With final figures yet to become available, the next step will then be to put everything together and compute what appears to be the outcome of this season, which is probably the easiest part of the task!!

I suppose a switch can now be made onto a bigger canvas!  The problem is also being experienced in several other parts of Scotland, either based on burgeoning breeding populations or increased presence in winter due to incoming birds from Iceland.  Understandably many farmers have expressed concerns about the situation and petitioned for action to be taken. Currently the Scottish Government is looking at the means by which such populations can be managed to ensure that a representative population remains in place, but that any exponential  increases are limited. Not the easiest of tasks I suggest!!  Licensed shooting can be carried out previous to the actual season commencing on 1st September each year and doubtless this has led to some containment of these populations, including here on Islay.

Another aspect which was central to concerns last year, but is less so this season, is the habit of the birds to enter ripening barley fields and generally cause mayhem!  Last year several fields were affected in this way, but the problem appears to be far more concentrated this season. With a full moon in evidence at present the  opportunity for the birds to feed during the night and undisturbed also becomes a reality. This is then followed by their use of sheltered, and far less obvious locations, during the day where they preen, rest and generally do very little!! Areas of moorland, isolated fields and even spells spent out on the larger lochs make counting a bit of a challenge.  Incidentally some of this barley is destined for use  by one of the island's accompanying important industries, that of producing malt whisky, although none of such fields appear to be affected this year

And so the story takes on an even more convoluted aspect and, I suspect, one might  hear strident calls for action from some who have never even set eyes on a Grey lag Goose !!