We saw our first Large Tortoiseshell not in Britain, where this is such a rare butterfly, but in Bulgaria; unfortunately for us, it was a very busy butterfly on a mission, and never once while in our sight did it pause long enough and close enough for a photograph. The only other place that we have seen the Large Tortoiseshell is in the Algarve region of southern Portugal, where we photographed the tired specimen shown on the left.
The undersides of the wings are cryptically coloured, as seen on the left, photographed at long range, again in the Algarve, by Rob Petley-Jones. (Getting close enough to one of these very skittish, fast-flying butterflies to take a good photograph is a real challenge!)
At one time this butterfly was a common occurrence in Britain, and the reason for its disappearance (other than the occasional 'lost' migrant or a release from captivity) is unclear. One obvious change is a dramatic reduction in the number of its preferred larval foodplants, various Elm trees (Ulmus species), due to Dutch elm disease.
In Britain this butterfly is now generally considered extinct as a breeding species, with a handful of migrants reported in 'good' years but none at all most years nowadays.
Breeding populations occur across central and southern mainland Europe and in northern Africa as well as into Asia.
Overwintering as hibernating adults, the butterflies emerge and mate in spring, laying their eggs on the leaves of Elms (mainly) and occasionally various other trees of the Populus genus - poplars, aspen etc. Very cccasionally willows (Salix species) are also used.