Nature enthusiasts are being asked to make a big effort to help Scotland’s smallest butterfly.

The Small Blue is rare in Scotland and urgent work is needed to help stabilise its population and provide the right habitat so it can spread to new areas, say conservationist.

Small Blue Butterfly Week is running until June 4 as part of a project to boost numbers in West Dunbartonshire and across Scotland.

Butterfly Conservation (BC) is organising events where the Small Blue is hanging on in colonies, sometimes as few as tens of adults.

During Small Blue Butterfly Week, volunteers will be asked to help look for the adult and its eggs and to help with planting its caterpillar food plant – Kidney Vetch.

Surveys will also take place to help identify any potential new breeding sites for the Small Blue.

Director of BC Scotland, Paul Kirkland, said: “We are really thrilled at the enthusiasm for Small Blue Week and the work carried out will inform habitat management that will be carried out in the autumn by landowners and BC volunteers to help the butterfly.

“Many areas occupied by the Small Blue have shrunk in size, are surrounded by inhospitable habitat and are threatened by scrub encroachment, so it’s vital we do this work to secure the butterfly’s future here in Scotland.”

The Small Blue can usually be seen flying from mid-May to late June and colonies are often confined to small patches of grassland where Kidney Vetch grows.

In Scotland the butterfly has been found in quarries and disused railway lines, but most colonies are found on steep coastal grasslands and sand dunes.

The Small Blue is much darker in appearance than Scotland’s most widespread blue butterfly, the Common Blue. Instead, the upper wings of the male Small Blue are almost black with a dusting of blue scales, whereas the female is more dark brown in colour.

Both sexes have an underside that is silvery-grey in colour, and not unlike that of the Holly Blue – another blue butterfly that is steadily colonising gardens up to the Central Belt.

If you would like to find out more about how you can help the Small Blue butterfly, email Scotland@butterflyconservation.org.