Spring migration is well underway now, with new bird species being sighted by keen-eyed local birders almost every day. My eyes are not so keen these days but, on Monday, with binoculars, I did manage to spot my first couple of House martins (Delichon urbicum) amongst a large flock of Sand martins feeding over Cardiff Bay. The two species can be difficult to tell apart especially in dull weather when the blue upper plumage of the House martin is not so obvious. However, when they’re flying, it was relatively easy to distinguish between the two species – the Sand martins have a brown bib whereas House martins have solid white underparts. As the birds were quite distant, I wasn’t able to get any clear photos so you’re being treated (ha!) to another of my very amateur drawings.