'Bumbarrel' is an old name for the Long-tailed Tit, everyone's favourite garden bird. And the reason they're called that is for the shape of their nest. It's almost spherical, with a little hole at the front, and made from a special weave of moss, lichen, spiders' webs and feathers.
I parked up in the small car park about 7.30am and walked east towards the rspb centre, before retracing my steps and on to the serin mound. Sun was shining and it was a pleasant walk. Spotted a family of Whitethroats with at least four full-grown young. Sedge Warbler still singing along with Cetti's. Lots of Swifts whizzing about and a few Martins. Two male Marsh Harriers one was I presume performing an impressive territorial display, with lots of twisting and turning with wings folded back and rolling, it also gave some regular calls. Although distant great to see.