Sunday 17th September 2017

On the 1st September, as I was standing on the back doorstep slurping my cuppa, a Hobby casually flew by and seemed to just reach out and grab a small bird from the air! It looked like a Meadow Pipit or something. Was nice to see but pity I wasn't holding my bins.

In recent years, September has been a very sunny month, with continuous, stiff easterly airflows - which sounds good, but we've tended to get stuck in week-long bird-less ruts, as there's been no change in the conditions. But this year the winds have been different, they keep returning to northerlies, and so this has meant many opportunities for seawatching. And so I was again on the rocks of Jaonneuse on 2nd. There was a similar selection as the seawatch a couple of days ago - 6 Great and 2 Arctic Skuas - and a Sooty Shearwater was also seen.

After a week with very few migrant land birds seen (although I got only my second patch Teal at Pulias), we tried again seawatching from Jaonneuse the next weekend on 9th. Again, the selection on offer was poor - Bonxies were up to 13 and there were 3 Sooty Shearwaters passing - but we didn't see anything unusual. However, as we sat there staring out to sea, we got a call off Mark G that he had just found a Buff-breasted Sandpiper down on the Old Aerodrome. So I abandoned my post and drove down to have a look at a decent rarity. Arriving, I found that it was right over the far side, not giving very good views at all in the bright sun (as can be seen from the deplorable photos below. Luckily Mark provided me with a couple of decent shots of the bird which he took when it was closer). Always a favourite wader amongst birders, it was present with a Ruff, and was the fifth I've seen on Guernsey.

Buff-breasted Sandpiper - L'Eree, 9 Sep 17

Buff-breasted Sandpiper - L'Eree, 9 Sep 17

Buff-breasted Sandpiper, L'Eree, 9 Sep 17 [Mark Guppy]

Buff-breasted Sandpiper, L'Eree, 9 Sep 17 [Mark Guppy]

Greenshank - Claire Mare, 12 Sep 17

Greenshank - Claire Mare, 12 Sep 17

Greenshank - Claire Mare, 12 Sep 17

We had another seawatch from Jaonneuse on 16th September and the numbers perked up quite a bit. We had 53 Manx and 3 Sooty Shearwaters, as well as 18 Common Scoter and a high number of 11 Fulmars. Bonxies were migrating through nicely and we had a total of 37, some passing quite close. We only had a few smaller skuas - just 2 Arctics - but I was pleased with the Pomarine that passed, despite it not giving the best of views. What this autumn is showing me is that, even with suitable winds, you really do have to put in the hours on Guernsey if you want to see some rare seabirds!

Despite being an island - which you may think means seabirds will pass at random spots -  the seabirds always pass Jaonneuse on (more or less) the same line. We pick them up from the seawatching position just as they are moving towards us, to the right of Alderney, watch them pass in front of that island, then seem to come a bit closer before turning out again and passing behind the reef. When we are lucky, quite a few birds will pass in front of the reef, but there seems very little variation in flight path (see below). I drew a few maps to consider this route.

It makes sense that we see the birds passing as described when you consider the possible routes taken (below). We presume that most of the birds we see have passed quite close to the Normandy peninsula - any birds further out in the Channel would have to change direction quite strongly if we were to pick them up. We also think this is the case due to the pattern of sightings. We always get some birds very early after dawn - we consider these are ones that have been in local waters overnight - and then a bit of a gap, before a pulse of sightings an hour or so later - which we presume are birds which have rounded the peninsula after spending the night in the Baie de Seine. Some coast-hugging birds will turn down the French coast and some other birds will pass through the gap between Guernsey and Jersey. These birds will probably turn before they get anywhere near us. There will be plenty of birds which will pass North of Alderney before turning south again. These birds will also be missed from Jaonneuse (unless the winds are so so strong they get blown through the gaps). If the birds we see are only the ones on the pink route below, these birds will need to duck south through the gap between Alderney and France, explaining why a northerly wind is vital to see any birds at all.

Below shows what the birds will see as they pass the Normandy peninsula (exaggerated as it is unlikely that they will be as high as shown). But it does show quite a narrow gap to aim for between Guernsey and Alderney, which may explain the very consistent route taken from our seawatching viewpoint.

Our route does appear to be the most popular one taken, according to the Channel Islands seawatching records (although we probably have the more extensive records anyway). But it is interesting to note that, if you take Brittany into account, the Guernsey route is indeed the most direct route into the Atlantic. But you can't see the distant Brittany peninsula from here, so perhaps the birds just know that it is the fastest way to go.

The final task of my summer holidays was to visit the Guernsey Museum store. Peter C had told me that there was a "Golden Eagle" in a case there which had been shot in Alderney in 1905 (or some similar year) and I had been meaning to check it out for a while now. I wanted to see it because, despite the claim, I was sure that the bird was not a Golden Eagle at all and was mis-labelled. I suspected it was almost certainly going to be a White-tailed Eagle, and a quick inspection revealed it was indeed a young White-tailed, as there a few old Channel Islands records of this species. The main ID features are set out below. Quite a spectacular bird and one that I would love to see soaring over the island nowadays. Whilst there I also took a look at some of the old butterfly and moth collections - many from the 19th Century, and many from the famous Victorian entomologist, W. A. Luff. I especially liked the Bath Whites from the famous 1945 influx. It was amazing that specimens that were so old were still so intact. When money is tight, spending on the curation of such collections is often cut, and that is when things get lost or damaged. It is such a shame we often do not value our natural history as much as we could.

White-tailed Eagle specimen from Alderney, Guernsey Museum stores.

White-tailed Eagle specimen from Alderney, Guernsey Museum stores.

The key features as to why the bird was White-tailed rather than Golden.

Polar Bears - Fort le Marchant, Sep 17

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