The Comma butterfly, which went extinct in Scotland in the 1870’s is spreading quickly through the southern half of the country, due to climate change. And if the current rate of spread continues, it should arrive in Inverness by 2017!
The butterfly is moving north at between 12 and 15km/year, and in the last ten years has successfully colonised the Borders, all of the Lothians, Fife and the southern parts of Tayside, with recent sightings reported from Dundee and Pitlochry.
Ragged wing edges distinguish this pretty orange and brown butterfly and make it unmistakeable. This, together with the distinctive white comma-shaped marking on the undersides, mean it is an easy butterfly for the public to record.
The butterfly can be seen in gardens and woodlands from May through to September, as it has two generations a year. Commas pass the winter as hibernating adult butterflies, and it was feared that last year’s exceptionally cold winter might have reduced Comma numbers, but recent sightings have shown that it is well established and thriving.
Paul Kirkland, Director of Butterfly Conservation Scotland said: “The large number of records we are now receiving from the public mean we can accurately track the butterfly’s re-colonisation of Scotland. The first butterflies seen a few years back were probably migrants from Northern England, but we know now that the Comma is once again breeding throughout southern Scotland
The colourful caterpillars were found earlier this year in Bridge of Allan feeding on elm, confirming breeding in the Central Belt. Sightings of adults are still being received, and this late in the year they will be butterflies looking for a sheltered place where they can spend the winter.
The Comma hibernates through the winter, along with other butterflies such as the Peacock, but you may still be lucky enough to spot one in the next couple of weeks in your garden or in woodland. The undersides of the Comma’s wings are highly camouflaged, which together with its ‘ragged’ outline help it to resemble a tattered dead leaf. This is important to help keep it safe from predators over the winter.
The northern range margin of the Comma (as defined by the average latitude of the 10 most northerly 10km grid squares with Comma records in each period, method of Hill et al 2002 and Hickling et al 2006) has moved northwards by:
150km in the past 10 years (i.e. between 1995-99 and 2005-2010) (15km per year)
362km in the past 30 years (i.e. between 1970-82 and 2005-2010) (12km per year)
This is a big shift, equivalent to the biggest shifts of other resident insects measured to date e.g. Common Darter dragonfly (13.8km per year, 346km northward shift between 1960-70 and 1985-95) (Hickling et al 2005) and Red-necked Footman moth (15.7km per year, 393 km northward shift between 1960-82 and 1983-2009) (Fox et al 2010). Other species, such as Peacock, Orange-tip and Ringlet have also spread north quickly in recent years.
Paul Kirkland, Director, Butterfly Conservation Scotland,
Tel: 01786 447753 Mobile: 07770 732825
Louise Keeling, Senior Publicity Officer, Butterfly Conservation
Phone 01929 406 005