Wednesday, 31 August 2016

Port Meadow - Marshworts & Wagtails

I don't usually blog about my local patch, Port Meadow, within the confines of my Gnome's Birding Diary, chiefly as I have a dedicated blog for that already. However, occasionally there will be things that occur on the Patch which might be of interest to my wider readership and so it is on this occasion with some rare plant news and also a comparatively interesting bird. So with apologies to those who've already read about this on the other blog, here it is again in more detail.

It all started on Saturday morning for the annual Port Meadow Creeping Marshwort survey. My botanist readers will know that Apium repens is a rare UK plant that is only found at Port Meadow. Well, I say only but actually the species guardian Judy Webb was so concerned about it's plight that a second back-up colony was established at another location nearby and in fact it's now doing much better at the back-up location than the original site. The trouble with Creeping Marshwort is that it is highly specialised. It's a pioneer plant, being the first to re-colonise mud banks after floods and relying on its low profile (it's "creeping" nature) to out-survive grazing by livestock which therefore will eat comparatively more of its competitor plants. So, it needs a flood meadow that is reasonably heavily grazed which is why it is to be found at Port Meadow. However, apparently, variations in how much flooding there is and how much grazing there is can make big differences to its survival rate each year. Somehow, despite past year-long floods and prolonged droughts, it still clings on in the Meadow though apparently it isn't doing that well in Europe either. As a matter of interest, due to it's pioneering nature, it moves around a lot and so isn't always found in the same place.

I met up with Judy Webb and one other botanist at the bottom of Walton Well Road at 10 a.m. on Saturday morning. Judy had brought along sample leaves of Creeping Marshwort as well as that look-alike Fools Watercress and she warned us that some of the Yellow-cresses can also look very similar. Having done this search previously, I knew just how tricky it can be though if I'm careful enough I like to think that I can generally pick out the genuine article. We started at the southern end and worked our way northwards. Predictably, because of its roaming nature it was no longer in many of the spots where it was usually found though some stronghold areas were still good. We even found one plant that was flowering.

The one flowering specimen

If you get your eye in then you can pick out the distinctive leaf shape.

Showing its creeping runners off to good affect here
The livestock showed a keen interest in undertakings!

There are lots of specialist plants on the Meadow that I'm pretty used to these days but I don't come across Marsh Arrowgrass so often
Whilst we searched diligently away I kept hearing the calling of Yellow Wagtails in amongst the livestock which is quite usual at this time of year. In fact, in the absence of any flood water, this is about the only bird life there is on the Meadow at present! I happened to spot one of them which was an adult female but seemed to have a very blue head and a clean white throat and which therefore had me thinking about female Blue-headed Wagtail. So after the end of the survey I said my farewells to Judy and headed back towards the cattle to see if I could get a photo. However try as I might, I couldn't get one before the weather started to close in and with a thunderstorm threatening I beat a hasty retreat.

The next day I went out again for a quick search for the Wagtail. There were loads of Yellow Wagtails dotted about in amongst the extensive cattle herd which must be well over fifty animals. It was hard work searching through them all as, unusually, many were hanging out in amongst the thicker grasses and thistle where they couldn't easily be seen on the ground. I did hear a different sounding call a couple of times: much more buzzy, bi-syllabic and pipit-like but I could never pin it down. Eventually, hunger started to get the better of me and I started to head back home, scanning through the straggler cows as I did so. As I went I spotted up a nice Wheatear, not such a common bird on the Meadow so I'm always pleased to see one. Suddenly I heard the call again and there was my bird! I whipped out my superzoom and started to pap away as best I could and fortunately this time the bird remained on show long enough for me to capture a few record shots. 

The Blue-headed Wagtail in the bag at last!

On the screen it looked reasonable though there was just a hint of yellow in the supercilium that I was a bit concerned about so I sent my shots to Ian Lewington who confirmed it as a genuine female Blue-headed Wagtail. Get in! So a nice weekend of botanising and birding on my local patch. Whilst it's hard work without the flood waters which make it the birdy place that it normally is, there's still something of interest to be seen there.

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