Cardiff Bay late afternoon from W side of the bay just along from Prospect Place/The Watermark flats: 2 Arctic Tern, 3 Common Tern, 1 stunning Ad summer Little Gull, plus 1000+ hirundines over the water, mostly Sand Martin & Swallow 50/50 approx, but with a few [say 30] House Martin, and a lot of Swift as I arrived [c.100] mostly high but as I left starting to fly low over the water.