Saturday, 29 September 2012

29 Sep '12- mahoosive movements in the Cuckmere

Early morning reports and garden birding

early on, Jon Curson reported a few Yellow Wagtails and Tree Pipits in a brief search of Seaford Head. It's been, to my understanding at least, a pretty good year for Yellow Wagtails, I've seen more of them (and til later in the year) than I've managed probably since autumn 2008, when they seemed so numerous I could count flocks of 20+ on the suburban fields I played football in! I normally don't see many Yellow Wagtails past about the 20th, but have had a few trickling through throughout this week, including 10+ at Portland Bird Observatory on the 22nd.

The morning/early afternoon were not especially bird-orientate for me, but I love autumn because migration is evident anywhere you go, at least around here. Hanging the washing up at around 12:30, I counted a small stream of Meadow Pipits, generally heading W or SW over the garden. This is the time of year when Siskin and other finch become evident on migration, and I picked one up by call as it flew over the garden. It was heading very low and in a NE direction, and almost landed in a Leyland Cypress 40 yards away before veering off to the north, Jon saw one do something similar earlier, I expect it's the same bird hanging around to feed up before continuing it's journey south. I've noticed an increase in reports of Siskin at garden feeders on the SOS, are these the returning winter birds or migrants, gratefully stocking up on an easy meal? Also seen was a Great Spotted Woodpecker, a none-too-common bird in the garden.

Cuckmere Haven- 13:30-15:00

A daylist for the Cuckmere managed 28 birds, but that wouldn't tell the full story at all! There were 2000+ Hirundines, with a ratio of about 70% Swallows and 30% House Martins. three SAND MARTINS felt almost like a rarity for me, they've been really hard to catch up with locally this year, and today smashed my previous 'last-of-year' record for the species by several days!  Also moving over were 2-300 Meadow Pipits, unsurprisingly a great day for one of the commonest autumn migrants on my patch. I picked up the calls of at least 10 YELLOW WAGTAIL as they passed south, these also being a record date! Is this year, which has been fantstic for them so far, the year I finally see an October Yellow Wag? (one of my odder birding ambitions).

As if that wasn't enough, I recorded four more record dates! Three were for Butterflies, Large White (of which there were still 100's), Small Heath (1), and Small Copper (4, and all the better as this is by far my favourite butterfly!). The latter two species were present in a small area (20 yards or so) about 50 metres NE of the Coastguard Cottages. Also seen today were 50+ Small Whites, 3-figure numbers of Red Admirals and a single Comma. The other record date of the day was a SPOTTED FLYCATCHER, feeding near the horse paddocks by the Golden Galleon. Otherwise grounded migrants where few and far-between, with perhaps 20 Chiffchaff, and a single, late Willow Warbler near Harry's Bush.

Small Copper (a.k.a the best butterfy in britain!) and
Small Heath, photographed near the Coastguard Cottges
However, migration was still in evidence, even in some of the commoner birds. seven Little Grebes on the meanders were the first returning birds of the winter (I can't wait til there's 30+ here!), and there was a slight inflation in gull numbers, with 200 Black-headed, 30 Herring and 12 Great Black-back at an estimate. However, the only ducks seen were 10-15 Mallard (the Shelducks go elsewhere to moult, but I'm surprised there are no Wigeon back yet), and the only waders were 5 or so Curlew heard calling from the fields of the west side of the valley.

one of several Black-headed Gulls present today

How much really moved through today?

when you think about it, this was the quietest time of day for birding, and yet the number of birds was phenomenal. so How many birds were migrating through the Cuckmere today? vis-mig is often at it's peak from first-light for about two hours, in this case 06:30-08:30. it then gradually tails off, and by the time I visited the Cuckmere should really be at quite a low rate. of course there are exceptions to that rule, but I still expect far more was moving through in the 7 hours of daylight before I arrived than the hour and a half I was there. so how much was really moving? I'll give my little estimate, which could of course be way off, but here it is anyway.

15,000+ Hirundines- days like this are pretty much annual in sussex, but still remarkable

1,500+ Meadow Pipits- could well have been more, but I'll try and be conservative. The rate of passage today was at least 150 an hour while I was present, and was probably higher in the morning!

100+ Yellow Wagtails- dad reported some overhead at Seaford Head this morning, and there were at least 10 moving over this afternoon.

In addition, Tree Pipit (JC) and Siskin (JC and myself) have been reported today, so small numbers of both those were probably moving over. Not forgetting the possibility of something rarer, maybe a Tawny Pip or a Citrine Wagtail among it's commoner relatives?
Rook at the Golden Galleon- totally irrelevant but it's a nice pic! 

Why today?

This question puzzled me a bit, as although the skies are very clear, the wind was generally S swinging round to NW today. However, I think this could have been last big push of british migrants leaving the country, which may well have been held up by the awful weather, and were today all leaving in one big stampede! The Westerly winds would support this theory, as often these birds appear to leave the country through areas like Portland, and could have been pushed further east towards us. Not forgetting the NE winds that brought additional Scandinavian and eastern birds into the country last weekend, these migrants have also probably been waiting around for a good day to leave. Some of you might think this question is a bit trivial, but if I remember this for the next time similar conditions occur, I'll be up at first light to see what's moving!

good birding to all

Liam C

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