Solitary Lesser Redpoll in my garden in the Outer Hebrides

For the past two weeks (approx) I’ve spotted a solitary Lesser Redpoll in my garden at the bird feeders. Niger seeds being its particular favourite.  I believe they are sometimes seen during the summer months in the Outer Hebrides, but is it usual for them to be solitary?  Might this lovely wee bird have strayed from the main flock?  Thank you.