Our website now lets you record the sex of the butterflies that you see but how do you know the difference between males and females?

With many Corfu species you can't tell them apart by eye but the good news is that there are still over 30 species where the male and female are visually different - all you need is to to read some clues and follow guidance on the website.

The first bit of help is that you will find the graphic below in various places on the website. It indicates that a particular species exhibits sexual dimorphism (the scientific term that means the sexes are visually distinguishable). So look out for this on species lists and on the species description pages where you will also find a scale of the ease with which you can tell the sexes apart (either Easy, Moderate or Difficult). Read the species descriptions, find the written differences between male and female, and compare those to photos (like the Meadow Brown pictured here) which you will find on the website but also on our Facebook page. Some of the photos on the website also have the symbol for male and female displayed on the photo where the sex can be identified.

Here are some clues for when you are out ‘in the field’ :

• Males often appear earlier than females. The phenomenon is called protandry and is seen especially in single generation species like Orange Tips.

• Behaviour is another important clue. A territorial stance on a leaf, followed by vigorous pursuit of other butterflies would be a demonstration of classical male behaviour whereas an insect skimming over vegetation might be a female looking for laying sites.

• Of course females tend to live longer and continue laying.

If you are able to record the sex of butterflies for CBC then you will be contributing valuable data to help understand life cycles.