Wednesday, 28 September 2016

Whiskered Tern on patch! Confession of a mis-ID...

As some readers may be aware, I had the fortune of finding this smart little beauty on my local patch of Argal Reservoir after returning to Falmouth a couple of weeks ago. Unfortunately, I managed to stuff up the immediate identification of the bird in the field, so thought I would write a post detailing the find and also the developing attention that it stimulated...

juvenile Whiskered Tern

My local stomping grounds whilst I am in Falmouth are the two nearby lakes of Argal and College - both sizeable bodies of water with a great mix of scrub, woodland, muddy edge and marsh surrounding the perimeter. I have been taking part in this year's Patchwork challenge here, but have been away all summer so my totals are pretty stunted! You can check out a full write-up of my patch here: My Patch write-up

So onto the find: we all make mistakes, and as the superb pioneer of Birding identifications Martin Garner always enjoyed reminding people, we shouldn't shy away from being wrong, and learn much from our errors! 

After a twelve hour train journey from Pwllheli to Falmouth the previous day, I had spent most of the 13th sorting out my accommodation, getting some supplies and generally settling in. The weather was overcast, with thunderous storms overnight and drizzly rain for most of the day. In the evening I decided to cycle down to Argal and take a look at patch...

On arrival, the first bird I saw was a small tern that was ranging around the edge of the reservoir with flicky, buoyant flight. My immediate thought in the excitement of the moment (which I later pinched myself for...) was something like: 'I wonder if it's a Whiskered Tern!?'

I then spent half an hour observing the bird as it flew around in the dying light, trying to suss out the ID. With a dark, mottled mantle, prominent black cap and what looked like fairly dusky upper wings (in the evening light) pointed towards a 'marsh' tern at any rate, and what looked like a rather large black shoulder splodge convinced me that it was a juvenile Black Tern - a good patch tick nonetheless.

It grew dark, and I returned home and took a look at the images on my laptop - they were pretty shoddy, grainy and very dark, and in most shots the shoulder marking seemed too big for anything other than a Black. White-winged would be very pale on the upperwings and have bright sides to the head/cheek. I published a couple of shots up on twitter after concluding on Childonias nigra

Over the next couple of hours, a couple of birders commented on my image and suggestions started circulating of Whiskered Tern - then I took another look at the bird, and after sending further images to some friends, realised I'd made a schoolboy error: it was a damn Whiskered Tern after all!!!

So what made it one? Well, after returning at 0630 the following morning and getting some superb views of the bird in good light conditions, it was so much more obvious: browny marbling marking on the scapulars, mantle and back, contrasting to very pale, silvery wings; very small shoulder mark, with a round head and distinctive black cap with very little white on the forehead; the head shape and bill structure was much very distinctive, and even the flight pattern was subtly different to that of a Black. So I have to say I was pretty annoyed at screwing up the ID! But there we are...

Over the following week, the bird remained faithful to the two lakes, fishing in frequent circuits around Argal, before heading down to College reservoir for a time and resting up on the floating oxygenation devices. I was really happy to see groups of birders enjoying the bird on a daily basis, and the smart little tern performed brilliantly from the 13th until the 17th. A very nice addition to my patch list, and a good learning curve for marsh tern ID - an area that I have very little experience with living on Bardsey!

College Reservoir is looking brilliant for wildfowl at the moment, with the habitats generally far more rich than this time last year due to lower water levels. I look forward to seeing what arrives and what I can find here in the coming months.

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