Sorting through some new photos I realised that I had previously misidentified a Great Helen (Papilio iswara) as a Red Helen (Papilio helenus). The Butterflies and moths (Lepidoptera) section has been updated to reflect this, and below also shows these two species side-by-side (Papilio iswara, left and Papilio helenus, right)
Robin.
P.S. Interestingly, the Great Helen (Papilio iswara) was first described from Penang Island itself!
Robin.
P.S. Interestingly, the Great Helen (Papilio iswara) was first described from Penang Island itself!