Friday, 22 September 2017

Horrid autumn- 22/9/17

A quiet passage day:
Point: Chiffchaff 2, Blackcap, Goldcrest, Linnet 5, Reed Bunting.
Viz mig (west): Gadwall 2 (south), Marsh Harrier (south-east), Black-tailed Godwit 10 (south), Sandwich Tern 13, Common Tern, Swallow 17, Meadow Pipit 20, Rock Pipit 1, Grey Wagtail (east).

After that, Horrid Hill 08:40-16:00.
What? Yup, I hung on a bit today. I often have two or three short birding session a day this time of year, all around the estuary. Today I'd decided on a count known as a 'through-the-tide count' (TTTC). Seven sets of counts, one every hour, to give an idea of how an area is utilised. What today's count showed is precisely why estuary WeBS counts should be coordinated; once the tide was in, the birds spent varying amounts of time in up to six different subsites. This is the track of the Grey Plovers:

The map was taken from the BTO webpages. In reality, not been counted by seven different people for some years, Nor, Friars and Bishop counted by boat when first I returned. The interchange between Rainham Saltings, Rainham Creek and Motney saltings clear, and I've found over the years there is also routine exchange between Copperhouse Marsh and the whole of the bay to the east of Horrid Hill.

Motney is blue, as it is an area with a counter vacancy. Doesn't mean they don't still need counters for the other sectors; some of the best organised estuary counts around the U.K. have subs (-titutes, nor marines) to count on the actual date if the regular counter can't make it. The regular might do a week later to keep their own run complete, and both can be submitted- supplemental counts are welcomed by the BTO. Some of the very best organised estuaries even try for annual LTCs (Low Tide Counts).

The important thing is for individual counters to really appreciate the importance of co-ordination. There is every possibility of a major mis-representation, and here on the Medway, such movements as shown will mean under-estimates; birds may spend a lot of the time out of your area while you're counting, and they certainly not spending equal amounts of time in each- the probability is you will miss some of them. So, going at different times of the high tide period really isn't the best for waders either. Just covered? Numbers higher along the shore, but these birds may well be mid-Channel come high tide itself.

Hopefully I'm not teaching many WeBS counters their job here. The reason I mention now is that I've been told by a couple of counters this winters' counts will be more coordinated. Absolutely brilliant news. I don't know if that includes the islands, clear that it really should; but if the boat can still only go weekdays, then one can dream of enough volunteers to get a mid-week count as well as the core date around the shore; results would be intriguing- the different rates of area usage weekdays to weekends would be clear for all to see.

Back at the results, you don't have to go all pictorial, you can just as easily chart. Here's a screengrab of three species counts that day- Oystercatcher, Curlew and Black-tailed Godwit:

Oystercatcher- on the top of the tide, some birds are getting pushed off and wandering (by now, main roost is over on the northern shore, Kingsnorth Power Station apron wall).

Curlew- all off to Oakham saltings for the high tide, after finishing feeding at Rainham Saltings. They can often choose Motney, but often avoid for a few days after disturbance.

Black-tailed Godwit- classic early season feeding effort on a low tide through from dawn- enough light to feed up out towards centre, have a pre-roost rest before tide even fully covers (today they chose Oakham island); different from later in season when have to work flats hard and follow right up Rainham Saltings/ Rainham Creek.

A TTTC is of the sort of survey your average consultant undertakes. They will be full of data, but if they get interpretation wrong, it then throws the lot. Why worth having a go at few yourselves. Here I've seen some very odd conclusions drawn for the north shore- statements that certain species do not use at certain times of the tide; utter pants, but unless the locals go about assimilating good information, hard to present. Even if you have a grasp of things, these sort of counts help refine your understanding, and you can argue your case so much easier.

Nothing wrong with playing at this either, on your own beach/shore/mudflat- say a mini-version, 3 or 4 hrs over the covered rising waters, 3 or 4 hours over the covering mud. You don't have to be as mad/sad/lonely as me. What I've been concentrating on these past few years is just the one central hour, mud-flat covering time, collecting data for all whole south shore areas up to three times a month. I'm beginning to suss what happens, but I know from carrying out a few TTTCs as well there's a lot to learn about those other hours. You could also very easily clarify/discover a few things about your own area. Grab your chairs, flasks and lunchboxes.. Shouldn't really leave it just to WeBS/LTCs and those bloomin' consultants.

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