Helping butterflies (Focus - May)

When I was a child, apart from the “cabbage whites”, which I now know to cover several species, the easiest to identify butterfly and frequently seen in the garden was the Small Tortoiseshell. This pretty, bright orange butterfly splashed with yellow, black, white and blue, was a regular on nectar-rich flowers, such as buddleia and sedum. It emerges in spring, after hibernating somewhere sheltered, and making use of its widespread and often abundant foodplant, the common nettle, produces two broods during the summer. It is the second that provides the adults to overwinter.

Unfortunately, this butterfly is becoming an increasingly rare sight. To coincide with the start of a new recording season, the UK Butterfly Monitoring Scheme (UKBMS) has just released its analysis of results for 2024. This is the 50th year of this scheme, which collects data from more than 3000 sites, as well as sightings from the Big Butterfly Count and from randomly selected kilometre squares throughout the country. The impressive long-term body of data the UKBMS collects allows us to assess  the state of the environment, the impacts of climate change and the progress of government policy initiatives to conserve biodiversity.

Last summer, many people were asking, “Where have all the butterflies gone?”, so many were awaiting the 2024 analysis with some concern and the results are extremely worrying.

It was one of the worst years since 1976, when UKBMS started. Although numbers always fluctuate up and down to a certain extent, for the first time on record more than half of our species are in long-term decline. It was the worst year, since counting began, for nine species, including the Small Tortoiseshell, and the second worst year for some of the butterflies of the wider countryside, like the Common Blue and Gatekeeper.

So, is there anything we can do personally to help the plight of our butterflies? Well, research shows that if you have a garden, leaving some of it to grow wild with long grass can increase butterfly numbers by up to 93%. Avoid mowing between April and September to allow adults to shelter, drink nectar from flowers, breed, lay eggs, and for their caterpillars to feed. Nectar rich flowers, either in your beds or in pots, will attract whatever butterflies may be in the area, and if you have an unmown patch with the right food plants, they may stop to breed. Long grass and nectar sources will benefit other species of wildlife as well, and multiplied up across many gardens in towns and villages, can help species which are struggling in the wider countryside.

I shall be keeping my fingers crossed for the wonderful Small Tortoiseshell. It is not a specialist butterfly restricted to nature reserves; we should be seeing it everywhere. An 86% decline since 1976 reminds us that when people talk about a biodiversity crisis, it is not just happening in the Amazon rainforest, it is here at home, and all around us.

​Andrew Graham