A SURVEY of the globally important Hebridean machair is shedding new light on some of its smallest – and world’s rarest – inhabitants.
Already known to be rich in plant and wildlife, recent results reveal that the islands’ machair is teeming with hundreds of species of beetle – several of which are very rare and some even on the brink of extinction.
As part of the Conserving Scottish Machair LIFE+ project – a partnership between RSPB, Scottish Natural Heritage, Comhairle nan Eilean Siar and the Scottish Crofting Federation – ecologists are currently surveying plots of machair across North and South Uist, Berneray and Benbecula.
They have sifted through over 30,000 beetles and identified 222 different species, including 36 which are new records to the islands.
Of these, 14 species have formal conservation status and three are noted on the IUCN Red List of Threatened Species, including the Silphid beetle (Thanatophilus dispar), which is extremely rare and in danger of extinction.
Rebecca Cotton, Machair LIFE+ Project Manager, said: “This shows that traditional methods of working the land by local crofters, such as applying seaweed as fertiliser, helps to create a biodiverse machair.
“We know that the machair is rich for birds and plants, but confirmation of the bug life is fantastic news.”
In addition to beetles, several species of native grasshoppers – such as the mottled grasshopper – were found in abundance across the islands, along with two rare species of bumblebee: the Moss carder bee and the Great Yellow Bumblebee.
Machair is a strip of land created by a combination of traditional crofting methods and coastal elements, and it is hoped the project surveys, which began last year and will run for the next two years, will offer an increased understanding of the relationship between agricultural management and biodiversity.
Insects are considered to be barometers for biodiversity and the success of agricultural systems in supporting wildlife. As well as being valuable in their own right, they are an essential food source for many rare and protected bird species such as the corncrake.
Commenting on the revealing survey results, Peter Hammond, Scientific Associate at the Natural History Museum in London, said: “These results demonstrate well how large-scale and systematic sampling can generate highly useful new data even in regions where, as with the Uists, the terrestrial macro-invertebrate fauna is considered to be already well documented.”