Small-male advantage in the territorial tropical butterfly Heliconius sara (Nymphalidae): A paradoxical strategy?

A natural territorial advantage associated with small size is reported for the first time, in males of the aposematic nymphalid butterfly Heliconius sara in subtropical Brazilian forest. Their wings are around 3% shorter that males caught away from mating territories. Smaller resident returned to territories over longer periods and it was observed that intruders will retreat faster when confronting smaller than average territory owners.