From the Sussex Wildlife Trust in England, about this video:
05 August 2015
This silver-washed fritillary and meadow brown were filmed in Hoe Wood at Woods Mill nature reserve by Reserve Manager, Steve Tillman. You can see the strange behavior of the silver-washed fritillary as it takes a persistent interest in the meadow brown. The fritillary followed the meadow brown around the woodland. This carried on for at least five minutes.
We asked our butterfly expert, Michael Blencowe, what he thought about the behaviour. Michael said “I think that it is likely that the silver-washed fritillary is trying to mate with the meadow brown. It is possible that something about the meadow brown – the orange on the wings perhaps – is acting as a trigger to the silver washed fritillary. Inter-species copulation is rare -but by no means unknown. I’ve seen this behaviour before between meadow browns and ringlets and even small tortoiseshells and meadow browns. However this pairing is new to me.”