The Spanish and Pyrenees brassy ringlets are now regarded as distinct
species, though older books treat them as subspecies. Their ranges are
absolutely disjoint and there has been no genetic interchange for
thousands of years, so it doesn't really matter either way - they are
without a doubt valid taxa and whether they are species or subspecies
is just a matter of where you choose to draw the line. The Spanish
brassy ringlet, Erebia hispania, is restricted to the Sierra Nevada, while the Pyrenees brassy ringlet, as the name suggests, is a Pyrenean endemic.
No other brassy ringlets fly in the Sierra Nevada, so identification
there is not a problem. In the Pyrenees, the common brassy ringlet
flies. This is broadly similar to the Pyrenees brassy ringlet but the
apical spots on the forewings, though usually touching, are not
actually conflated into one, in the way they are in the Pyrenees brassy
ringlet. The red on the forewing is also less extensive in common
brassy ringlet, reaching less far towards the trailing edge, and the
hindwing spots are less marked. In my experience, the underside
hindwing of the Pyrenees brassy ringlet is less contrastingly marked,
and slightly sandy in the female.
These two brassy ringlets both fly on grassy slopes, from 1650m to
2300m in the Pyrenees and above about 1800m in the Sierra Nevada. The
caterpillars feed on various grasses including sheep's fescue and
hibernate just once, the adults flying in a single generation from June
to August, depending on latitude and altitude (earlier in the south and
at lower altitudes within the same mountain range).