James Silvey, Habitats and Species Officer with RSPB Scotland, brings us this latest blog on keeping your eyes peeled when out in the wild - you never know what you might find!
Copinsay, credit: Christine Hall.
Scotland’s islands are amazing places. Step off the ferry or plane into Scotland’s archipelago and you’ll often find yourself transported to a bizarre wildlife 'mirror land', where species thought of as rare on the mainland can be relatively common, and common species seen elsewhere across the country become extremely rare or absent entirely.
I'll give you an example. Travel to Orkney and hen harriers can become a frequent (but no less magnificent) sight, where on Tiree the sight of a wood pigeon would make the local birding news.
The lesson to be learnt from these island aberrations is never discount anything you see on an island because you never know what may turn up.
It's a lesson that paid off in June this year when a team of RSPB Scotland staff were on the uninhabited island of Copinsay off the east coast of mainland Orkney. The team were there to survey for the rare great yellow bumble bee, a species that in other areas is extremely difficult to see, yet on Copinsay it’s the second most common bee encountered (see what I mean?).
During the surveys, one of the local staff spotted a dragonfly resting on a patch of grass. This is unusual in itself as Copinsay has very limited fresh water and isn’t the ideal habitat for an insect that spends much of its life feasting on tadpoles and small aquatic invertebrates.
After a couple of quick photos for later identification the dragonfly was released and the bumblebee surveys continued. Later the dragonfly was identified by staff as a common darter (Sympetrum striolatum), fairly rare for Orkney but common on the mainland, a good result.
The record was sent off for verification and largely forgotten about until an email came through a week later rejecting the identification of common darter in favour of the much rarer red-veined darter (Sympetrum fonscolombii). This migrant dragonfly is a frequent visitor to the south of England, however this record was not only a first for Orkney but a first for northern Scotland with the next nearest record coming from Dundee.
Its presence on Copinsay on a cloudy day in June was probably a result of favourable winds and the chance in a million luck of a group of surveyors out looking for a very different kind of insect.