Papillon du jour (butterflies) flying in the middle of the night.

[Niklas Wahlberg]

At 21:28 30.01.2002 +0000, Paul Cherubini wrote:

>How do we even know migratory butterflies can see in the middle of the night?

And how do we know that butterflies use sight for their navigation? I don't 
know, does anybody else know? Butterflies are after all descendants of 
moths. Have you ever been hit by a moth at night? There are many species of 
butterflies that fly in the dark, mainly satyrines and morphines in the 
tropics. Mark mentioned Melanitis sometime ago, there are lots of other 
species. There is a hypothesis saying that butterflies evolved their 
diurnal behaviour in order to avoid bat predation. So why can't butterflies 
retain their ancestral ability of navigating in the dark? Sure this is just 
speculation, perhaps somebody else on the list has more knowledge? By the 
way, how do monarchs navigate when they migrate? Do they "see" where north 
and south are?

>Can any migratory butterfly detect the movement of an approaching six
>foot tall homo sapien on a warm night and take evasive action?
>I doubt it.

I repeat, ever been hit by a moth at night?

>If the wind disturbs a tree full of monarchs or migratory
>Painted Ladies at night do they take flight and re-gather on the leeward
>side of trees out of the wind? Or do they all crash to the ground below
>the tree where they are subject to being eaten by mice and ground dwelling
>invertebrates? The latter in my experience.

Like Bob said, "they're too sleepy", ie their body temps are too low to 
allow activity. The question is, can an already active butterfly continue 
to be active when night falls?

Cheers,
Niklas

>

Niklas Wahlberg
Department of Zoology
Stockholm University
S-106 91 Stockholm
SWEDEN

Phone: +46 8 164047
Fax:   +46 8 167715

http://www.zoologi.su.se/research/wahlberg/


 
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