To the friends and recorders of the Corfu Butterfly Atlas. We have been looking closely at our maps of the Southern Swallowtail (Papilio alexanor), and a fascinating mystery has emerged. On the slopes of Mt. Pantokrator, this beautiful butterfly seems to be "playing hide and seek." Our records show it is doing well near the coast, in the mid-altitudes around 400m, and again up near the summit. But in between these areas—specifically around the 200m and 600m marks—there is a strange silence. We have almost no sightings at all.

Is it a Gap or a "Blind Spot"?

We don't know yet if the Southern Swallowtail is truly missing from these heights or if we simply haven't had enough eyes on the ground there. If these "gaps" are real, it means the butterfly’s home is fragmented into isolated islands, making it much harder for them to survive a changing climate. We need to fill the gaps.

This spring, we are asking for a few "mountain explorers" to help us check these specific quiet zones. If you are out walking, we would love for you to target:

• The Lower Slopes: Between 150 m and 250 m elevation.
• The High Ridges: Between 600 m and 650 m elevation.

Why your "Zero" matters

In science, knowing where a butterfly isn't is just as important as knowing where it is. If you spend an hour in these zones and see plenty of other butterflies but not the Southern Swallowtail, please tell us! It is important that you record all the butterfly species you see at these altitudes because that "zero" for the Southern Swallowtail would be a vital piece of the puzzle that helps us prove where the gaps truly are.

Even though the Corfu Butterfly Survey officially ended on the 31st December 2025, we have kept the recording facility on our website still open so that we can correct for any gaps in our data, like this particular puzzle. Please, help us turn our "blind spots" into a clear map for conservation. Thank you.

P.S. our earliest record for this species begin on the week starting the 09 April, it then peaks on the week beginning 07 May and our final records are for the week starting the 25 June.