Val d'Aran, Pyrenees, July 2004, in the middle of a road!
Dead female (road casualty), Val d'Aran, July 2003
Wings of a road casualty - Female, North Italy, 2014 - upperside
Wings of a road casualty - Female, North Italy - underside
Forewing against a centimetre ruler
Forewing against a centimetre ruler
Distribution
The woodland grayling is widespread and locally common in much
of the southern half of Europe. As some of the pictures above sadly
show, it has a predilection for roads, where it may be seen probing the
hot tarmac with its proboscis or flying clumsily across, buffeted by
passing articulated vehicles. When not directly braving the traffic, it
often rests up on roadside barriers. As its name suggests, it is
usually found near trees, where it may be seen resting on the bark in
the heat of the day, but this is true also of the similar rock
grayling, so is little help in identifying the species.
In the western parts of its range, it is most similar to the rock
grayling, Hipparchia
hermione,
and can be very difficult to separate from this butterfly. The most
constant feature is size: excluding outliers, all woodland graylings
are larger than all rock graylings (forewing length, base to tip,
>
33mm in woodland grayling, < 33mm in rock grayling). Size is
notoriously hard to judge in the field, however, and virtually
impossible from a photograph, so this is not always helpful. Other
features are more variable, and what works in one population may not
work in another. With that caveat, I have observed several useful
differences. On the underside hindwing, the white discal band is
generally broader, more chalky white and more outwardly diffuse in
woodland grayling. In rock grayling the outer contour follows the inner
one more closely. The inner contour is typically more angular in rock
grayling, sidestepping the cell as it crosses the wing to give a more
or less well defined prominence. On the forewing underside, the region
around the apical eyespot is useful to look at. In rock grayling, there
is a rather well defined, dark 'eyebrow' above the eye, separated from
it by clear orange. In woodland grayling this feature is much less well
defined. On the male upperside, when this is visible, the apical
regions of the woodland grayling are darkened by diffuse scaling,
obscuring the eyespot more than in rock grayling. None of these wing
features, however, is universal or constant, and where both species fly
it is not always possible to say which is in front of you. In the
Balkans and south-eastern Europe, the eastern rock grayling, is similar
but is smaller and typically has a narrower and less obvious white band
on the underside hindwing.
The woodland grayling flies in a single brood from June to September in
grassy, bushy places, usually in or near woods. The caterpillars feed
on various grasses, including upright brome, red fescue and tor grass.
The species hibernates as a caterpillar.
