White Winged Black Tern at Tyttenhanger

A White Winged Black Tern was found at Tyttenhanger on Tuesday. Its a rather rare bird for Herts, with only seven previous records, usually at Wilstone/Tring and two together at Hillfield. Usually they don't linger, so most birders went down that evening, or early the next morning as it roosted overnight.
I didn't. Stevenage to Tyttenhanger involves going up and down the two lane  section of the A1M which features on the traffic news most rush hours, and a short very busy stretch of the A414 at London Colney. Basically I was stuffed, I had a couple of appointments as well, immediately after work so there was no realistic chance of seeing it.
It lingered into Thursday, my last day at work for a week so there was hope. At breakfast on Friday, Tom Spellar put out a message that it was still there, and once the worst of the school run was over I departed (via Knebworth as the A1 was as usual very slow) and got to London Colney just after 9am.
It was a nice, cool sunny morning with a bit of a breeze, and Robins ticking in the hedges as I walked rapidly down to the main pit where I found Rupert Evershed scoping from the gate. He mentioned the two Ruff-a nice bonus Herts year list and pointed me towards Willow Farm lake where I soon joined a couple of guys up from London.
We walked along the Fishing Lake bank, without seeing a great deal apart from large numbers of House Martins, along with Sand Martins and Swallows. Seeing a couple of birders on the causeway I saw the familiar face of Lee Evans, and it was clear the Tern wasn't showing. Rather despondently we
arrived at the causeway, and at the same time the Tern appeared, flying around only a few feet away from us. Over the course of the next hour we were treated to stunning views as it did innumerable circuits of the small lake, dropping down to the water in front of us from time to time.
For the first time this year I regretted taking the GX8 and 100-400mm lens as the bird was too close, too fast and too agile. I had to back the zoom off to 200mm and even then I had problems. The 300mm Nikkor and the D3s would have been a better choice, but I managed to obtain a lot of excellent images.

Lee mentioned a male Redstart in the big field hedge and he also wanted to see the Ruff so we both went back to the main pit. No sign of the Ruff so walked up the hedge without seeing anything apart from a few Reed Buntings. One of the locals was at the top and pointed out where the Redstart had been, and Lee went off to the viewpoint as the Ruff were visible from there-as was the Tern, now roosting on the mud.
Eventually we got good views of the Redstart low down from a range of about 100yds, occasionally perched in the hedge, but sometimes dropping onto the ground to feed. I eventually managed to get a bit closer and got a few images, before being joined by Alan Meadows and a few other Tern twitchers.