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Hello All,

The following skipper was seen last week in the South Of France (Lerin Islands, Canne). Have pondered long and hard and come with a couple of options. Would dearly love an expert cast an opinion.

Regards Kev Ling

Carcharodus alceae (Mallow Skipper), I guess.

Yes - a definite mallow skipper!

Guy

Skippers can cross stretches of ocean then. I know these tiny islands are only a 15 minute ferry ride from Cannes harbour, but I'm still surprised these butterflies are flying across open water to get to them.

If there are resident colonies on these islands they might initially have arrived there by various means, as adults or early stages - even on the ferry! But it would surprise me if they didn't also make it over every so often on their own, as adults, blown by westerlies or northerlies. And of course, during the last Ice Age these were not islands but very much part of the mainland, probably covered in mainland forest.

You are right though, that skippers are often very sedentary. There are Lulworth skippers in the Canaries on at least four of the islands, but they are so isolated from mainland populations they have evolved into what is now described as a separate species, T. christi. I believe all the Canary Lulworth skippers are christi, implying butterflies moved between the islands during or after the process of speciation.

Guy

padfield wrote:If there are resident colonies on these islands they might initially have arrived there by various means, as adults or early stages - even on the ferry! But it would surprise me if they didn't also make it over every so often on their own, as adults, blown by westerlies or northerlies. And of course, during the last Ice Age these were not islands but very much part of the mainland, probably covered in mainland forest.

You are right though, that skippers are often very sedentary. There are Lulworth skippers in the Canaries on at least four of the islands, but they are so isolated from mainland populations they have evolved into what is now described as a separate species, T. christi. I believe all the Canary Lulworth skippers are christi, implying butterflies moved between the islands during or after the process of speciation.

Guy

I've been to the Iles des Lérins, Guy, and they're tiny - the largest of the two is probably half the size of the Calf of Man. Okay, they're only 2 or 3 km off the coast, but even that would be sufficient to deter a sedentary butterfly from making the journey.

I can't believe there's been a continuous population there since the last ice age, so one is prone to conclude that they fly there periodically from the mainland.