Andy Smith, local butterfly expert and the county recorder for Guernsey, Herm and Sark, has been reviewing local butterfly numbers over the summer of 2024 following the publication of the Big Butterfly Count in the UK. This highlighted a drop of 50% year-on-year and declines in nearly all UK species.

“Since retirement, I have been a full-time butterfly recorder, and Pollinator Project member and my gut feeling is that it’s the same picture here- but most worrying of all is that some species are teetering on the brink of local extinction. The general consensus is that this has been one of, if not the, worst year for a very long time. 

The Small Tortoiseshell, with only four sightings reported so far this year, must be considered critically endangered. Even Sark, a wildlife haven locally, is not immune- it seems that the Dark Green Fritillary, thought only to breed in Sark within the Channel Islands, might possibly be extinct- none were reported in 2024 there at all. So, along with reducing numbers, we are possibly already beginning to see species slip away. In all my years of recording (more than a quarter of a century) I cannot recall as poor a season as this.’ 

The reasons behind this aren’t complicated, but are inter-linked. The combination of pesticide use, more land used for development and the loss of habitats are all well-known factors. But we are now seeing the effects of climate change- not just the cold wet summer- but the summer drought 2 years ago dramatically reduced the number of wild nettle patches. These are the food plant of the Small Tortoiseshell and the Peacock butterfly.  

So what can we do about this?

Well there is no magic wand, we can’t instantly have more butterflies. The starting point is to protect what we’ve got.

Step 1 Cut out pesticides

It doesn’t matter if they are herbicides, fungicides or insecticides, they all have a detrimental effect on nature including bees and butterflies. Use cultural methods-raking or cutting, or vinegar or plant the plants you want to see.

Step 2 Plant more butterfly friendly plants

Butterflies on the wing need nectar, but their caterpillars need food too. Our top 10 for the garden are nettles, oak trees, birds foot trefoil, blackthorn, verbena, knapweeds, marjoram, buddleia, red valerian and hemp agrimony. They can all be easily grown in gardens, and are good for a range of butterflies and other pollinators.

If you want more ideas, you can borrow a copy of Dave Goulson’s book Gardening for Bumblebees from the Guille-Allès library. Or butterflies in your garden from the RHS is a good article.

Step 3 Leave them alone

During the winter, butterflies will either hibernate as adults or as pupae- we sometimes call them a chrysalis. You are most likely to see them in corners of sheds or garages, but they also hide in log piles, even old rabbit holes anywhere they won’t get disturbed. If you do find them fluttering about in the winter, carefully catch them up and put them back in a cool building.

Step 4 Leave fallen fruit

A few apples, plums or even blackberries rotting in the garden can provide a rich source of food for butterflies in the autumn. They are stocking up on reserves to try and survive the winter, and before they go into hibernation. The good news is, you don’t have to do anything to help!

If you take these steps, who knows you might be the person who brings back a Guernsey butterfly from the brink.

For more information and to get involved, please contact us.

We will be featuring butterflies in our Spring 2025 Schools programme and you could play a part in that.