Island butterflies, grasshoppers and lizards in Corsica: 25 – 29th Sep

My motivation in joining Naturetrek’s autumn tour of Corsica was pretty much to explore another Mediterranean island I had aspired to visit. No special wildlife agenda was involved, aside of adding the previous post’s birds to my life list, but there were also some previously unseen insects and reptiles on the itinerary. Most of all an autumn trip to look back upon is of benefit during the difficult days of short daylight that now lie ahead, and on seeing this tour advertised in an e-Newsletter it just looked like an interesting one.

The week’s most frequent sightings in butterfly-friendly places were Southern Grayling and the local race of Wall Brown, while large and graceful though mostly worn Cardinal would waft through proceedings when they chose to. All three of these were new to me to some extent. There was very little odonata interest on the trip, with just a few common dragonflies seen and one localised damselfly, Island Bluetail on the final day after I lost my camera.

The range of Southern Grayling (Hipparchia aristaeus) extends from North Africa through Corsica, Sardinia and Sicily into the southern Balkans, then onward into Greece and Turkey. The trip’s one true lifer displays subtle differences in markings from the more widespread Grayling (Hipparchia semele) that extends northwards into Great Britain and southern Scandinavia. The most marked features to my mind were the larger ocelli (top wing eye dots) and all round brighter orange tone. A noticeable behavioural characteristic was a higher and more erratic flight pattern compared to the northerly equivalent that generally keep closer to the ground.

The Tyrrhenian – Corsica, Sardinia and some small islands – population of Wall Brown is accorded specific status Lasiommata tigellus by some sources, but this is not a generally agreed endemic. Once again the butterflies seen seemed brighter orange than the abundant and widespread Lasiommata megera that occurs in Britain, while the upper wing bars of the males appeared especially bold. In common with Wall Brown across Europe, the Corsican butterflies (pictured below) could be seen one after another in dry, rocky places even in lower light conditions when much else had ceased flying.

The Cardinal Fritillary, usually referred to simply as Cardinal is distributed widely through southern and central Europe and north Africa. Across much of that range they fly between May and July, though north African populations produce a second brood in August and September. There must be some blurring of time scales in Mediterranean islands, and as clear was that most of the specimens observed on this trip were far from fresh. I had seen this butterfly once before, but cannot remember where.

Cardinal is a thicker set and less graceful butterfly than Silver-washed Fritillary, with which it could be confused until red in the underwings is revealed. But I did not capture that feature and will have to make do with the record shot (below) until I can uncover more recently hatched butterflies at some future date. Though fading, this individual was still the week’s best.

cardinal.1701 corsica

Cardinal

The full butterfly list for the trip was a not unusual Mediterranean selection comprising Swallowtail, Large White, Small White, Clouded Yellow, Brimstone, Small Copper, Lang’s Short-tailed Blue, Holly Blue, Common Blue, Brown Argus, Southern White Admiral, Red Admiral, Silver-washed Fritillary, Queen of Spain Fritillary, Speckled Wood (southern race), Wall Brown, Small Heath, Meadow Brown, Southern Grayling and Grizzled Skipper.

A few of those are pictured above and below.

I can usually find some inclination to pay attention to Grasshoppers when in the southern European field, if not already pre-occupied with butterflies and dragonflies. I regard the first-named as probably the next most interesting insect order. They are noticeable here due to some species’ habit of flying past the approaching walker between waist and head height, and in the process revealing brightly coloured underwing flashes. But I can rarely match what I might manage to photograph with field guides.

That is hardly surprising since there are up to 600 different grasshopper species in southern Europe, compared to 30 in Great Britain, and many display a complex degree of variation. Hence most published guides illustrate a representative sample only. So I will not attempt to name the insects of dry, stony places in the following pictures precisely. From my European field guide (the one by Michael Chinery – see here) I would estimate most of these (pictured below) are from the species groups Psophus, Oedipoda and Odaleus.

The second sequence (below) conveys just what masters of camouflage many grasshoppers can be. It is almost as if they adapt their colouration to match the background. That is until some are disturbed and fly on an erratic course flashing their hindwings of red, green or blue. This is a survival strategy since hunting birds, for instance think they are chasing colourful prey. When the grasshopper settles the predator is still looking for a brightly toned insect that has to all intents disappeared. Human observers can likewise be deceived, it being easy to mistake these fly pasts for butterflies.

One species is unmistakeable however, the weird and wonderful looking though perhaps unflatteringly named Mediterranean Slant-faced Grasshopper (Acrida ungarica). A common insect of the region, it can be either green or brown and inhabits damp, grassy locations including coastal marshes. These images (below) were captured with some difficulty and much cursing in a dune system in the Golfe de Sagone on Corsica’s west coast. Oh you beauty!

Corsica has four different lizards, of which three are endemic to the Tyrrhenian islands. The most frequently encountered was Tyrrhenian Wall Lizard, a smallish and slim member of the lacertid group of which there are many species in southern Europe. TWL is found in a range of dry habitats from sea level up to 1800m but is commonest at middle altitudes. Their colouring varies considerably (pictured below). I believe the streaky brown individuals are females, while males tend to be greener, often striped and the brightest green are juveniles. There is also a reticulated male form with more of a bluish hue.

Tyrrrenian Wall Lizard colour forms (above) and reticulated male (below)

tyrrhenian wall lizard.1710 corsica

We found the larger and more robust Bedriaga’s Rock Lizard twice. This is a distinctly flattened, medium-sized species (pictured below) with pointed snout and often bulging cheeks. The upper side is usually boldly reticulated, sometimes spotted and rarely striped. BRL is found in montane habitat up to 2500m and is an avid climber, frequenting cliffs, rocky outcrops, stony surfaces, dry stone walls and other man-made structures including buildings.

The third endemic is the Pygmy Algyroides, that we failed to find. This diminutive lizard is largely nocturnal and mostly conceals itself by day, so seeing one can involve a lot of rock and log turning. Italian Wall Lizard (below, left) another lacertid has been introduced to Corsica and replaces it’s Tyrrenhian equivalent in some coastal areas. Collins describes this as a vigorous, opportunistic lizard found at low altitudes in grassy places, open fields, woodland edges and sandy coastal areas; as well as around human habitation. IWL was also observed in two locations during this trip.

Lastly, at our second hotel in the Restonica valley Moorish Gecko (above, right) emerged in the early evening on each day of our stay, to bask in artificial light on the hotel terrace. These mainly nocturnal, soft-skinned lizards have large heads and eyes with cat-like vertical pupils, and adhesive pads on their toes. They are very agile climbers, often hunting on walls and inside buildings. I had not seen any species of gecko previously.

This completes the more notable, new and different wildlife encountered during my most recent excursion to southern Europe. I may include a fuller and more detailed account, with scenic pictures in this site’s trip report section in due course, when time allows.

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