Simon's comma question

[Padfield]

Simon asked (on the January competition page) why commas have a bright white comma on the hindwing, when otherwise they are so well camouflaged.

Here's a pure guess:

The comma's legs and antennae are the biggest giveaway. If a potential predator happens to be looking in the direction of the comma, perhaps the white mark, which doesn't spell 'butterfly' or 'food' in any obvious way, draws its eyes away from the legs and antennae, like a decoy. The predator checks out the white mark, sees nothing special to eat, and moves on.



Without the distraction of the comma, wouldn't all those appendages be more readily noticed?

Just a thought.

Guy

[Matsukaze]

I think the whitish legs and the comma may be further camouflage measures.

The butterfly's legs can look like small dead twigs. In the picture below, the Comma appears to have three legs on the left-hand side, whereas it should of course only have two, like it does on the right-hand side; the 'central' leg on the left-hand side (which is an actual leg) looks like it extends under the large twig it is resting against and for some distance beyond.





The comma could also serve as part of the 'dead leaf attached to a branch' camouflage, as a hole or tear in the leaf. Viewed against the sky it would tend to take on a similar colour.

[Simon C]

Thanks for picking up on the question. Both suggestions seem very plausible - I especially like the idea that it might be an attempt to replicate a tear in the wing. Devious.

That's a wonderful photo Guy, and Chris, in your picture the Comma looks like a ballerina doing exercises at a ballet bar!

Cheers,

Simon

[Trev Sawyer]

To my (warped?) mind, the 'comma' looks a bit like an eye... If you half close your eyes and squint a bit, the top photo looks like the brown head of lizard/turtle looking from left to right, with the 'comma' being it's eye and the top wing being it's nose. So, maybe a predator thinks there is a larger beast hidden behind vegetation to the left

Ok, I'll get my coat


Trev

[Martin]

Sounds plausible to me Trevor.

Martin.

[Trev Sawyer]

Yeah Martin,
but you're as mad as I am

[Martin]

You have a point...

[55bloke]

All these replies imply that the Comma made some sort of rational decision to have a white mark on it's hind wing, with a logical process of reasoning behind it. Surely, in fact, the mark- along with all the other features- are a result of a genetic mutation which just happened to confir some sort of added protection, and was therefore selected for. Who knows what that added protection was? Maybe it was that it looked like a tear in the leaf, or a drop of water, but the butterfly had no choice in the process.

[Padfield]

I don't think anyone was suggesting for a minute that the butterfly chose its markings! I, for one, am a committed neoDarwinist. But that doesn't mean they can't come to represent quite specific things, as a result of quite specific forces operating during selection. You say, 'Who knows what that added protection was?' Well, we'd like to!! Not because it's important but just because it's interesting.

Guy

[Charles Nicol]

would the marking on the Silver Y moth be conferring the same benefit as the comma on the Comma ?

charles

[Dave McCormick]

I think it may be similar. I saw this: http://www.theimagefile.com/?Action=VF&id=22265 and took a few mins to see the silver y moth on the pic

[Charles Nicol]

also the mother shipton moth has a distinctive T shaped marking.

charles