Unexpected birdlife at King's College, Cambridge

We haven't been on any bird searches recently, not since we went to the New Forest, but at the weekend we were given a nice little surprise sighting. Sometimes you wait around for hours and find nothing, and sometimes the birds find you.

We went to Cambridge University with Rose's parents. As we were waiting in the tall stone entrance to King's College (pictured), for Rose's dad to get the keys to go punting, we heard some twittering from above.

In between the ornate vaults of the ceiling, round grey nests were attached. They looked a bit like they were made out of cement.  As we were watching them, a few little black and white birds peeped out and dived over our heads across the lawn towards the chapel.

They were housemartins. We had seen something swooping about earlier on and we weren't sure if it was a swift or a swallow. Turns out it was neither, but in many ways the housemartin is like a cross between the two: stocky like the swift but with the colouring of a swallow and a tail almost as pointy. I had never seen a live housemartin before. I don't know about Rose. It was a real treat. 

Thanks to Martin Cook at Cambridge for taking these photos for me (and thanks to Rose's parents for taking us there on a day out).