I have noticed that Monarchs seem, for all their size to be either pacifists or wimps ( depending on your viewpoint) when 
confronted by an aggressive though much smaller species.
They fly away meekly.
		Terri 
On Aug 3, 2010, at 9:44 PM, David Hoag wrote:

> Late this afternoon, a Monarch dropped from overhead from a thistle, 
> falling to the grass at my feet.  After picking up the Monarch, 
> I discovered that it was tenaciously clinging to the abdomen of 
> a Viceroy -- presumably the same Viceroy that had been nectaring 
> on a nearby thistle a few minutes earlier.  20-30 seconds after I had 
> pried open the Vicery's wings, the Monarch released its catch.
> 
>    On Sunday, a territorial male Black Swallowtail, 
> which was patrolling a thistle and wildcarrot filled ditch, 
> aggressively chased away a Monarch, and another species 
> (painted lady?); driving both to high altitudes
> before returning to cruise up and down the ditch.
> 
> Some leps encounterd on Sunday -- estimated numbers.
> Black Swallowtail 7
> Cabbage White 4
> Clouded Sulphur 15
> Orange Sulphur 5
> Eastern Tailed Blue 1
> Summer Azure 16
> Great Spangled Fritillary 5
> Meadow Fritillary 2
> Crescent (sp) many!
> Question Mark 5
> Eastern Comma 1
> American & Painted Lady 5 
> Red Admiral 10
> Viceroy 5
> Northern Pearly-eye 2
> Eyed Brown 8
> Common Ringlet many!!!
> Monarch 8
> Silver-spotted Skipper 1 (& 100's of larvae).
> Least Skipper 1
> 
> Dave Hoag, Grand Isle
> 
> 
> .</HTML>