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I saw this yesterday on a hillside in the Swansea Valley. It was in rush pasture alongside a mountain stream on the side of a mountain. Why is it flying in early May? I thought it maybe a Small Heath but looks as though it has two spots.

walescottages wrote: ↑Tue May 12, 2020 6:25 am Why is it flying in early May? I thought it maybe a Small Heath but looks as though it has two spots.

Because your first instinct was correct! It's a Small Heath. They are on the wing now and the habitat (mountainside meadow) is very typical of Small Heath (at least in the sense that you may not see much else there!).

They can sometimes have a second spot (see these two, photographed in Lincs and Cumbria respectively).

I wouldn't expect to see Gatekeepers prior to July (at least not in south Wales!)

Small Heaths DO sometimes possess spots on the underside hindwings; it's a highly variable butterfly.

This is one I photographed last month in Swansea:

Thanks both! I never knew a Small Heath could have a second spot.

It's worth pointing out that when trying to ID a butterfly its usually better to look at the whole rather than one isolated aspect (except for a few very similar sp.). Time of year, habitat, size, how they fly will all help and, as with all wildlife, natural variation automatically means no two individuals will look the identical. Small Heaths will normally have the one eye spot but as others have said they occasionally have an extra. On the other hand they sometimes have none. And although Gatekeepers usually have two pupils in their eyespot, sometimes they have just a single one and sometimes they have lots! There's a recurring theme that crops up later in the year you see banded around on facebook groups when meadow Browns and Gatekeepers are on the wing together. Two pupils = Gatekeeper, one pupil = Meadow Brown. Whilst this is correct 95% of the time it's also not foolproof .
This isn't meant to confuse you but it just proves that butterflies don't read the books we write about them. When you get your eye in you'll find you'll end up with the right species quickly just because it 'looks right'

I thought that was a very good description of variation, Bugboy.

Perhaps I could add that when a scientist 'defines' a species, it is accompanied by a 'Type' specimen, which forms the 'official' reference for that species. During the 19th century, when so much of the groundwork on species definitions was done, it became something of a 'sport' to find variations from the 'type' and give each of these variations its own name - these are referred to as 'aberrations' and. for some species there are lots of them. You'll find many of them are described in the species lists on the Home Page of this website.

Once you are familiar with all the species on the 'British List', you can go on to try and find as many named 'aberrations' as you can - it can become a lifetime task