Here are some notes regarding the Stint sp. at Patrington Haven, East Yorkshire.
I was the second person on site this morning and Brett Richards and I watched the bird at relatively close range (c.30 m). This is a brief summary of my thoughts. If anyone would like further information please PM me.
My first reaction on seeing the bird was "This looks like a Little Stint" (albeit a rather long-legged individual). I am not persuaded that it is a Long-toed and the general impression was, as I say, of a particularly long-legged Little Stint.
I found the tarsus to be notably long but Brett was more concerned about the length of the tibiae, which was also long. The leg colour I noted as 'dark' but Brett was able to discern a more olive tone than the typical dark / black of Little Stint. The bird was an adult.
I have come back home to look at pictures on the internet and I can't find a Long-toed Stint image that matches the bird.
The legs looked especially long when the bird was hovering / flying from one feeding spot to another (it was with a group of active Dunlin). We noted the length of the hind toe to be less than the width of the tarsus though. My understanding is that Long-toed should show a hind toe longer than the tarsus width...
The bird did appear to show a split supercilium and possibly also the bulbous pale base to the supercilium. It did not show a pale base to the lower mandible.
On ocassion the bird did display the upright jizz often associated with Long-toed but only more so when it was feeding in deeper vegetation.
The bird was rather attenuated in shape, another feature apparently incongruous with Long-toed.
If it is a Long-toed it is a very atypical individual.
There was a second stint (presumably the Little Stint which Brett had alongside the bird the previous evening) which appeared briefly with the original bird but I wasn't able to compare them as the flock flew not long after the second bird appeared. Apparently, the previous evening, the two stints did look very different from each other, at least as far as leg length was concerned.
The bird was photographed and videoed and pictures will no doubt appear online later today.